Home » PQRS is a rhombus of side 16cm. The diagonal |QS| = 20cm. Calculate, correct to…

PQRS is a rhombus of side 16cm. The diagonal |QS| = 20cm. Calculate, correct to…

PQRS is a rhombus of side 16cm. The diagonal |QS| = 20cm. Calculate, correct to the nearest degree, ∠PQR

A.
51^o
B.
64^o
C.
77^o
D.
103^o

Correct Answer: Option D

Explanation

cos(alpha) = (frac{10}{16}) = 0.625
(alpha) = cos^-1(0.625)
= 51.3^o
∠PQR = 2(alpha)
= 2(51.3^o)
= 102.6
= 103^o