6th Grade Math Textbook, Fundamentals

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11-2

Draw Three-Dimensional Figures

Objective To interpret and create isometric drawings • To interpret and create

orthographic drawings

Computer game designers often use drawings
to help them design game figures. How can a
three-dimensional figure be represented by a
two-dimensional drawing?

To represent a three-dimensional figure by a
two-dimensional drawing, you can use isometric
and orthographic drawings.

An is a pictorial view created

on an isometric dot grid of a three-dimensional

figure. It is made by three types of lines:

• vertical lines


• 30° lines going to the right


• 30° lines going to the left
  The drawing at the right shows an isometric drawing
  of a cube. The 90º angles in the faces of the cube are
  drawn as 120º and 60º angles.
  Do you see a regular hexagon in the drawing?
  An isometric drawing of a cube is a regular hexagon,
  but you imagine a cube when you look at it!
  When making an isometric drawing, it is helpful to
  refer to a model. To draw a prism, first use cubes to
  build a 5 2 2 rectangular prism. Have the prism
  rest on a 5 2 face. Turn the prism so you are looking
  at one of the vertical edges.

Now follow the steps below. Each step is associated with

a number in the drawing.

Draw a 2-unit vertical line segment for the height.

From the bottom of the vertical line segment, draw

a 30º line segment to the right that is 5 units long.

From the bottom of the vertical line segment, draw

a 30º line segment to the left that is 2 units wide.

From the endpoints of the connected line segments,

draw two vertical line segments, each 2 units tall.

Connect the endpoints of the vertical line segments.

Draw the length and width parallel to the length

and width you drew in step 5.

isometric drawing

VLGH

WRS

IURQW

120°

30° 30°

60°

isometric drawing