i. ∠XYZ = 135°
□WXYZ is a parallelogram.
∠XWZ = ∠XYZ
∴ ∠XWZ = 135° …..(i)
ii. ∠YZW + ∠XYZ = 180° [Adjacent angles of a
parallelogram are supplementary]
∴ ∠YZW + 135°= 180° [From (i)]
∴ ∠YZW = 180°- 135°
∴ ∠YZW = 45°
iii. l(OY) = 5 cm [Given]
l(OY) = 1/2(WY) [Diagonals of a parallelogram bisect each other]
∴ l(WY) = 2 x l(OY) = 2 x 5
∴ l(WY) = 10 cm
∴∠XWZ = 135°, ∠YZW = 45°, l(WY) = 10 cm