Question

Draw the isometric projection of a triangular prism (base edge 35 mm, length 60 mm). It is placed on H.P. with one of its long edges and its axis is perpendicular to V.P. Indicate the direction of viewing. Give all the dimensions.

Hint:

In isometric projection, lines parallel to the isometric axes retain their scale; others are constructed using the isometric grid or compass.

Answer 1

We are asked to draw the isometric projection of a triangular prism with the following characteristics:
- Base edge = 35 mm
- Prism length (axis length) = 60 mm
- Placed on H.P. (Horizontal Plane) with one base edge
- Axis is perpendicular to V.P. (Vertical Plane)
Interpretation of orientation:
- Since the prism is placed on H.P., its triangular base lies flat on the horizontal plane.
- Axis perpendicular to V.P. means the prism faces the viewer head-on; one of its rectangular faces is parallel to the picture plane.
Construction steps:
1. Start by drawing the isometric axes at 30°, 90°, and 150°.
2. Construct the triangular base using isometric projection (base edge = 35 mm). Place it horizontally on the bottom face.
3. Project all three vertices upward using vertical lines to represent the length of the prism = 60 mm.
4. Join corresponding top points to complete the triangular prism.
5. Indicate the direction of viewing using a labeled arrow.
6. Apply dimensions using isometric dimensions — do not rotate text or dimension lines.
Dimensions to be shown:
- Base edge = 35 mm
- Prism height (axis length) = 60 mm
- Side edges and thickness lines of triangle
Label the drawing:
Title: Isometric Projection of a Triangular Prism (Scale 1:1)
Projection Type: Isometric Projection (using isometric scale from part a)