Question

ABCD is a rhombus with ∠ABC = 30°. The measure of ∠ACD (in degrees) is _____ .

• A. 75

Answer 1

The correct option is A 75

∠ABC = ${30}^{\circ }$ (Given)

∠BCD = ${180}^{\circ }$ - ${30}^{\circ }$ = ${150}^{\circ }$ (Adjacent angles of a parallelogram are supplementary)

Here, AC is the diagonal.
In a rhombus, the diagonals are the angle bisectors.

∠ACD = $\frac{1}{2}$ ∠BCD = $\frac{1}{2}$ × ${150}^{\circ }$ = ${75}^{\circ }$