Question

Find the unknown angle​

Answer 1

A = 45°

Explanation:

All angles in a triangle add up to 180°.

We know that one angle in the triangle is 90° (this is known because of the small square).

Hence:

A + A + 90° = 180°

Simplify

2A + 90° = 180°

Rearrange

2A = 180 - 90

2A = 90

Divide both sides by 2, so that A is by itself

A = 45°