Q8 of 109 Page 330

The diagonals of a rectangle ABCD intersect at the point O. If ∠BOC = 50°, then ∠OAD = ?

∠BOC = ∠AOD (Vertically opposite angles)

Angle AOD = 50°

In ∆ AOD, Since, the diagonals are equal, thus the bisectors will also be equal)

Thus, OA = OD

∴ ∠OAD = ∠ODA

= (180° - 50°)

= (130°)

= 65°

∴ Option C is correct

In the given figure, lines l, m and n are parallel lines and the lines p and q are transversals. If AB = 5 cm, BC = 15 cm, then DE : EF = ?

ABCD is a rectangle in which diagonal BD bisects ∠B. Show that ABCD is a square.

Match the following column:

Column I	Column II
(a) Sum of all the angles of a quadrilateral is	(p) Right angles
(b) In a \|\|gm, the angle bisectors of two adjacent angles intersect at	(q) Rectangle
(c) Angle bisectors of a \|\|gm form a	(r) 90^o
(d) The diagonals of a square are equal and bisect each other at an angle of	(s) 4 right angles

The correct answer is:

(a) -……, (b) -……..,

The diagonals of a rhombus, ABCD intersect at the point O. If ∠BDC = 50°, then ∠OAB = ?