Question

Investigate :

Use strips and fasteners to make a triangle and a quadrilateral.

Try to push inward at any one vertex of the triangle. Do the same to the quadrilateral. Is the triangle distorted? Is the quadrilateral distorted? Is the triangle rigid?

Why is it that structures like electric towers make use of triangular shapes and not quadrilaterals?

Answer 1

A triangle is a rigid figure as compared to a quadrilateral. Therefore pressing on any vertex of the triangle does not cause any distortion in its shape. This is the reason why structures like power towers use triangular shapes, not quadrilateral shapes.