Question

Given that ABCD is a rhombus, what is the value of x?

в
с
(3x + 12)"
A
O A. 19.5
B. 78
O C. 15.8
O D. 26
E. 52
ОО
F. Cannot be determined

Answer 1

Explanation:

It’s A

Answer 2

A. 19.5

Explanation:

Diagonals of a rhombus intersect at right angles. Therefore the angle opposite to AD = 90°.

Thus:

90° + x + 3x + 12 = 180° (sum of ∆)

Add like terms

102 + 4x = 180

Subtract 102 from each side

4x = 180 - 102

4x = 78

Subdue both sides by 4

x = 19.5