Which statements are true? select three options,
planes x and y intersect at a right angle a and elie in
plane x and do not intersect lies in plane y
and & are parallel
and
are parallel.
and
are perpendicular
and it must intersect.
0
cg lies in plane x
rs lies in plane x
intro
done

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