Exterior angle equals to the sum of two opposite interior angle.

The given angle B is for right angle.

Consider the smaller triangle and apply sum of two sides property.

First find the missing side of rhombus and then find area of square.

Isosceles triangle has two equal sides.

Apply Pythagoras theorem.

The total sum of all the angles is 180.

First find the missing side in rectangle.Then apply the formula A = L x B.

Let each angle be x, 2x and 3x and total be 180.

Apply Pythagoras theorem.