Why Do Electric Towers Use Triangular Shape?

Structures like electric towers make use of triangular shape so that they could not be distorted and they could be rigid.

Why are electric towers shaped that way?

T-shaped design

The design features electricity cables strung below a cross-arm atop a single pole instead of an Eiffel-Tower-style lattice A-frame with a series of arms holding the electricity cables. This results in reduced the visual impact on the environment.

Why triangle is not distorted?

On pushing inward at any one vertex of the triangle, the triangle is not distorted, However, the quadrilateral is distorted. Hence, a triangle is a rigid figure. This is why structures like electric towers make use of triangular shapes and not quadrilaterals.