Question

A triangular plane has sides 75mm, 70mm, and 60mm. It is a right-angled triangle with one side as 75mm, making an angle of 60 degrees with the projection. Find its angles with H.P. (auxiliary method).

a) 30°, 60°, 90°
b) 60°, 45°, 75°
c) 90°, 45°, 45°
d) 75°, 60°, 45°

Answer 1

The angles of the triangle with the horizontal plane are 30 degrees, 60 degrees, and 90 degrees, given that it is a right-angled triangle with one angle of 60 degrees.

Step-by-step explanation:

The student is asking about finding the angles with the horizontal plane (H.P.) for a right-angled triangle with side lengths of 75mm, 70mm, and 60mm, where one side is 75mm making an angle of 60 degrees with the projection.

Since the triangle is right-angled, and one of the angles is given as 60 degrees, we can deduce the angles using the properties of a right-angled triangle. The sum of angles in any triangle is 180 degrees. Given that one angle is 90 degrees (as it is a right-angled triangle) and another angle is 60 degrees, we can calculate the third angle.

To find the third angle: 180 degrees - 90 degrees (right angle) - 60 degrees (given angle) = 30 degrees.

Thus, the angles of the triangle with the horizontal plane are 30 degrees, 60 degrees, and 90 degrees.