An isometric drawing for a three-dimensional figure is different from its orthographic drawing primarily in the way it represents the spatial relationships and angles of the figure.
To clarify the options:
A. **An isometric drawing shows the bottom of the figure** - This is not necessarily true because an isometric drawing typically shows three faces of the figure simultaneously without emphasizing any particular bottom or top face.
B. **An isometric drawing shows the figure’s measurements with different scales** - This is incorrect. An isometric drawing maintains equal scales along the three axes (usually 120 degrees apart), ensuring that dimensions are proportional and can be measured directly along these axes.
C. **An isometric drawing uses dashed lines to represent hidden edges** - While it is true that hidden edges can be represented by dashed lines in some types of drawings, this is not a defining characteristic of isometric drawings. Dashed lines can be used in both isometric and orthographic drawings to show hidden features.
D. **An isometric drawing uses dot paper** - This is misleading. Dot paper (or isometric grid paper) can be used to help draw isometric drawings, but it is not a defining feature of isometric drawings themselves. Isometric drawings can be created without dot paper as well.
The fundamental difference lies in the perspective and the way spatial information is conveyed. An isometric drawing provides a pseudo-3D view where three axes are represented at equal angles (typically 120 degrees apart), allowing a more realistic depiction of how the object looks in space. Orthographic drawings, in contrast, use multiple views (typically front, top, and side) to represent the object using perpendicular projections, showing only two dimensions in each view.
Therefore, none of the options (A, B, C, or D) exactly capture the key difference. The primary distinction is in perspective representation, not in whether they show the bottom, different scales, use dashed lines, or utilize dot paper.
How is an isometric drawing for a three-dimensional figure different from its orthographic drawing?
A.
An isometric drawing shows the bottom of the figure.
B.
An isometric drawing shows the figure’s measurements with different scales.
C.
An isometric drawing uses dashed lines to represent hidden edges.
D.
An isometric drawing uses dot paper.
1 answer