Question

One angle of a parallelogram is twice the adjacent angle. Angles of the parallelogram are

• A. 60°,100°,180°,20°
• B. 140°,20°,120°,80°
• C. 60°,120°,60°,120°
• D. 100°,80°,100°,80°

Answer 1

The correct option is C

60°,120°,60°,120°

Let one angle be x and the adjacent angle be y.

Given, x = 2y--- (i)

x + y = ${180}^{\circ }$---- (ii) (sum of adjacent angles of a parallelogram is ${180}^{\circ }$)

Substitute (i) in (ii), we get

$\Rightarrow$ y = ${60}^{\circ }$

$\Rightarrow$ x = 2y

$\Rightarrow$ x = ${120}^{\circ }$

Therefore, the angles of the parallelogram are ${60}^{\circ }$, ${120}^{\circ }$, ${60}^{\circ }$, ${120}^{\circ }$