Question

If a perpendicular drawn from an obtuse-angled vertex of a rhombus to the
opposite side bisects the side, all angles of the rhombus are
(a) 70°, 110°, 70°, 110°
(b) 40°, 140°, 40°, 140°
(c) 50°, 130°, 50°, 130°
(d) 60°, 120°, 60°, 120°​

Answer 1



GIVEN: Rhombus ABCD , AB = BC = CD= AD = 2a , DM= MC = a , & BM is perpendicular to DC

Let < C = x deg

In right triangle BMC

Cos x = a/2a = 1/2

=> x = 60 deg

=> <A = < C = 60 deg

& < B = < D = 120 deg

I hope (D)is the right answer