In the diagram, PQRS is a circle center O. PQR is a diameter and ∠PRQ = 40°. Calculate ∠QSR.

Each side of a regular convex polygon subtends an angle of 30° at its center. Calculate each interior angle

If the interior angles of hexagon are 107°, 2x°, 150°, 95°, (2x-15)° and 123°, find x.

In the diagram, POS and ROT are straight lines, OPQR is a parallelogram. |OS| = |OT| and ∠OST = 50°. Calculate ∠OPQ.

Given that x = -\(\frac{1}{2}\) and  y = 4 evaluate 3x\(^2y+xy^2\)