In the diagram, PQR is a circle with center O. If ∠OPQ = 48°, find the value of M.

In the diagram, PQ is a straight line. If m = \(\frac{1}{2}\) (x + y + z), find value of m.

In the diagram, O is the center of the circle. \(\overline{PQ}\) and \(\overline{RS}\)  are tangents to the circle. Find the value of (M + N).

P(-6, 1) and Q(6, 6) are the two ends of the diameter of a given circle. Calculate the radius.

 In the diagram, ∠ABC and ∠BCD are right angles, ∠BAD = t and ∠EDF = 70°. Find the value of t.