If the perimeter of a square is 80, which is the area?

Perimeter of a  square = 4 * length of each side

80 = 4 * length

length = 20 cm.

Area of a square = length * length

Area = 20 * 20 = 400 sq.cm

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq