Isosceles Triangle Problem No.3 - Projection of Planes - Engineering Drawing | Summary and Q&A

TL;DR

In this video, a problem on the projection of planes is solved by determining the projections of an isosceles triangular plate and finding the inclination of the plate with the horizontal plane.

Key Insights

• 🫲 The left-hand side is chosen as a reference in the projection of planes, with edges or corners placed on the left side.

Transcript

Read and summarize the transcript of this video on Glasp Reader (beta).

Questions & Answers

Q: How is the initial projection of the isosceles triangular plate drawn?

The isosceles triangle is drawn in the top view as a straight horizontal line in the front view due to the nature of plane projections. The 50 mm long edge is placed in the horizontal plane (hp).

Q: How is the isosceles triangular plate transformed into an equilateral triangle in the top view?

To transform the isosceles triangle into an equilateral triangle in the top view, point C is lifted while keeping points A and B fixed. This reduces the altitude until all sides (AB, BC, and AC) are equal.

Q: How is the inclined view of the plate determined?

By lifting point C and reducing the altitude, the front view of the plate appears as an inclined line. The angle between this inclined line and the horizontal plane (hp) is measured and found to be 54 degrees.

Q: What are the dimensions of the isosceles and equilateral triangles?

The dimensions of both triangles are 50 mm for the base, 80 mm for the altitude, and 50 mm for each side of the equilateral triangle in the top view.

Summary & Key Takeaways

• The problem involves an isosceles triangular plate with a 50 mm base and 80 mm altitude. The goal is to draw the projections of the plate, considering that its 50 mm long edge is in the horizontal plane (hp).

• The isosceles triangle is drawn in the top view and appears as a straight horizontal line in the front view due to the nature of plane projections.

• To make the isosceles triangle appear as an equilateral triangle in the top view, point C is lifted and the altitude is reduced until the sides AB, BC, and AC are equal. The inclined view of the plate is determined to be 54 degrees with the horizontal plane (hp).