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G3 · Top, Front and Side Views of 3-D Objects

Learn to model 3-d objects and draw their top, front, and side views through clear examples and targeted practice.

Alberta Grade 11 Mathematics

Geometry

Read and draw top, front, and side views

A cabinet maker may need a clear plan before building a storage box. A single picture can show that the box is three-dimensional, but it may not show every measurement clearly. Top, front, and side views each show the object from one direction. Together, these flat views give useful information about its shape and size. In this lesson, you will model simple objects and make those views. A view is a flat drawing of the outline and details visible when looking straight at an object from a chosen direction.

What you will learn

  • Describe a 3-D object using its length, width, and height.
  • Model a simple object with a sketch or unit cubes.
  • Draw and label its top, front, and side views.
  • Check that the views agree with the object’s dimensions.

Start with the object and its dimensions

A three-dimensional object has length, width, and height. Length and width describe the base. Height describes how tall the object is. Use units such as centimetres or metres, and keep the units consistent within a model.
A rectangular prism is a box-shaped solid. For example, a storage box could be 60 cm long, 30 cm wide, and 40 cm high. A model is a drawing or other representation that helps describe an object. It does not need to look exactly like a photograph; it needs to show the dimensions and shape clearly.
Before drawing views, choose which face will be the front. The front view looks straight at that face. The top view looks down from above. The side view looks straight at one side. State which side view you mean if the object could be viewed from either side.
top: length and width; front: length and height; side: width and height
  • Choose and label the front before making the views.
  • The top view shows length and width.
  • The front view shows length and height.
  • The side view shows width and height.

Make each view match the object

An orthographic view is a flat view made by looking straight at an object from one direction. It avoids the slanting appearance of a perspective sketch. Each view shows only two dimensions, so it cannot show depth by itself.
For a plain rectangular prism, each view is a rectangle. The top view’s horizontal side represents the object’s length, and its other side represents its width. The front view uses length and height. The side view uses width and height. Label the dimensions so a reader does not have to guess what each side means.
For a more complex object, draw the shape from each direction and include visible edges or changes in outline. A model made from unit cubes can help: count the cubes along each direction, then draw the outline seen from above, in front, and from the side. A unit cube is a cube used as one equal-sized part of a model. Do not add a line to a view unless it represents an edge or change that can be seen from that direction.
A useful check is to compare the dimensions shared by two views. The length in the top view must match the length in the front view. The height in the front view must match the height in the side view. The width in the top view must match the width in the side view.
top: (l,w),front: (l,h),side: (w,h)\text{top: }(l,w),\quad \text{front: }(l,h),\quad \text{side: }(w,h)
  • Draw each view as if looking straight toward the object.
  • Views that share a dimension must show the same measurement for it.
  • Use visible outlines and edges; do not add details that cannot be seen.

A clear drawing is a useful model

A quick three-dimensional sketch helps a reader picture the object. Label its length, width, and height. Then draw the three flat views separately and label each view. The views are not three different objects. They are three ways of recording the same object.
The views do not have to be drawn at full size unless a task asks for that. They should still be proportional enough to make the shape understandable, and their labels must give the actual measurements. If the views are not drawn to scale, do not use a ruler measurement from the page as if it were an actual object measurement.
Before finishing, check the labels, units, and shared dimensions. Ask whether each view could come from the same object. A front view that is taller than the side view when the heights should match signals a drawing or labelling error.
  • Label the object and each view.
  • Write units with measurements.
  • Check matching dimensions across views.

Which dimensions appear in each view?

ViewFirst dimensionSecond dimension
TopLengthWidth
FrontLengthHeight
Right sideWidthHeight

Worked example

Views of a storage box

A closed storage box is 60 cm long, 30 cm wide, and 40 cm high. Its long face is the front. Describe the shape and dimensions of its top, front, and right-side views.
Rectangular storage box
TOPFRONTSIDE60 × 30 cm60 × 40 cm30 × 40 cmEach view shows two dimensions.

A simple rectangular box shown with its three dimensions for making matching orthographic views.

  1. Identify the object
    The box is a rectangular prism. Its stated measurements are length 60 cm, width 30 cm, and height 40 cm. The long face is the front, so the front view uses the length and height.
  2. Match dimensions to views
    Looking down shows the length and width. Looking straight at the front shows length and height. Looking at the right side shows width and height. Each view is therefore a rectangle with the corresponding pair of measurements.
    top: 60 cm×30 cm;front: 60 cm×40 cm;right side: 30 cm×40 cm\text{top: }60\text{ cm}\times30\text{ cm};\quad \text{front: }60\text{ cm}\times40\text{ cm};\quad \text{right side: }30\text{ cm}\times40\text{ cm}
Answer: The top view is a 60 cm by 30 cm rectangle. The front view is a 60 cm by 40 cm rectangle. The right-side view is a 30 cm by 40 cm rectangle.
Check: The top and front views both use the 60 cm length. The front and side views both use the 40 cm height. The top and side views both use the 30 cm width.

Worked example

Check a set of proposed views

A rectangular display plinth is 80 cm long, 50 cm wide, and 20 cm high. A draft labels its top view 80 cm by 50 cm, its front view 80 cm by 20 cm, and its right-side view 55 cm by 20 cm. Find and correct the error.
Rectangular display plinth
TOPFRONTSIDE80 × 50 cm80 × 20 cm50 × 20 cmEach view shows two dimensions.

The stated dimensions give the correct width and height for checking the right-side view.

  1. Recall what the side view shows
    The right-side view shows the object's width and height. The height is 20 cm, and the width is 50 cm. Therefore, the 55 cm label cannot describe this box's right-side view.
  2. Correct the measurement
    Replace 55 cm with the stated width, 50 cm. Then compare shared dimensions: the top and side views both use width, and the front and side views both use height.
    right side: 50 cm×20 cm\text{right side: }50\text{ cm}\times20\text{ cm}
Answer: The error is the 55 cm side-view measurement. The right-side view should be 50 cm by 20 cm.
Check: The corrected side view shares the 50 cm width with the top view and the 20 cm height with the front view.

Worked example

Model a low platform

A low rectangular platform is 1.2 m long, 0.8 m wide, and 0.25 m high. The long face is the front. State the measurements in each view and explain one reasonableness check.
Low rectangular platform
TOPFRONTSIDE1.2 × 0.8 m1.2 × 0.25 m0.8 × 0.25 mEach view shows two dimensions.

A rectangular platform model with length, width, and height labelled by the view measurements.

  1. Assign the dimensions
    The platform is a rectangular prism. Its long face is the front, so the front view uses 1.2 m and 0.25 m. No conversion is needed because all measurements use metres.
  2. Describe all three views
    The top view uses length and width. The front view uses length and height. The right-side view uses width and height. Each view is rectangular because the platform has straight rectangular faces.
    top: 1.2 m×0.8 m;front: 1.2 m×0.25 m;right side: 0.8 m×0.25 m\text{top: }1.2\text{ m}\times0.8\text{ m};\quad \text{front: }1.2\text{ m}\times0.25\text{ m};\quad \text{right side: }0.8\text{ m}\times0.25\text{ m}
Answer: The top view is 1.2 m by 0.8 m. The front view is 1.2 m by 0.25 m. The right-side view is 0.8 m by 0.25 m.
Check: The platform is much longer and wider than it is high, which fits the description of a low platform. The 1.2 m length matches in the top and front views; the 0.25 m height matches in the front and side views.

Common mistakes and how to avoid them

Using the height as one of the top-view dimensions.
Correction: The top view looks down, so it shows length and width, not height.
Giving the right-side view the object's length.
Correction: The right-side view shows width and height. Use the chosen front direction to tell length from width.
Drawing three views that do not agree on shared dimensions.
Correction: Compare the length in the top and front views, the width in the top and side views, and the height in the front and side views.
Treating an unlabelled sketch measurement as an actual dimension.
Correction: Label each view and give the object's dimensions with units. Do not assume a sketch is drawn to scale.

Lesson summary

  • A 3-D object can be described by its length, width, and height.
  • The top view shows length and width; the front shows length and height; the side shows width and height.
  • Choose the front direction, label views, and include units.
  • Check that dimensions shared between views agree.

Check your understanding

Question 1

A box is 45 cm long, 25 cm wide, and 30 cm high. What dimensions belong in its top view?
  1. 45 cm by 25 cm
  2. 45 cm by 30 cm
  3. 25 cm by 30 cm
  4. 30 cm by 30 cm
Show answer and explanation
45 cm by 25 cm
The top view looks down on the object and shows length and width.

Question 2

A rectangular object is 70 cm long, 40 cm wide, and 15 cm high. Which view should show 40 cm and 15 cm?
  1. Top view
  2. Front view
  3. Right-side view
  4. All three views
Show answer and explanation
Right-side view
The right-side view shows width and height.

Question 3

A box has a front-view height of 32 cm. What height should its right-side view show?
  1. The object's length
  2. The object's width
  3. 32 cm
  4. It cannot be determined because each view has a different height
Show answer and explanation
32 cm
The front and side views show the same object height, so the height must match.

Key terms

Three-dimensional object
An object with length, width, and height.
Model
A drawing or representation that shows useful information about an object.
Orthographic view
A flat drawing made by looking straight at an object from one direction.
Rectangular prism
A box-shaped solid with rectangular faces.
Unit cube
One equal-sized cube used as a part of a model.

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Published by DoAssignment. This reviewed lesson follows Alberta Grade 11 Mathematics (Math 20-3), expectation G3. It is a study resource, not an official curriculum publication.

Before publication, content is checked for structure, mathematical or chemical notation, calculations, course boundaries, and readability. Errors can still occur, so corrections are welcomed.

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