You construct a picture frame with a diagonal piece attached to the back for support, as shown. Can you tell from the dimensions whether the cormers of the frame are right angles? Explain.

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

if you was gonna solve for a, a is a   < -12

answer: apothems is your answer

step-by-step explanation: hope u get it right