Question

In a parallelogram $ABCD$, $\angle$$A$=${60}^{\circ }$, then-

• A. $\angle$$B$=${60}^{\circ }$
• B. $\angle$$C$=${60}^{\circ }$
• C. $\angle$$D$=${120}^{\circ }$
• D. $\angle$$B$=${120}^{\circ }$

Answer 1

Answer: (B), (C), (D)

The correct options are
B $\angle$$C$=${60}^{\circ }$
C $\angle$$D$=${120}^{\circ }$
D $\angle$$B$=${120}^{\circ }$

A quadrilateral is a parallelogram, if opposite pair of angles are equal. In parallelogram $ABCD$
$\Rightarrow$ $\angle$$A$ = $\angle$$C$
$\Rightarrow$$\angle$$C$ = ${60}^{\circ }$
In a parallelogram -
$\Rightarrow$ $\angle$$A$+ $\angle$$B$ + $\angle$$C$ + $\angle$$D$ = ${360}^{\circ }$
$\Rightarrow$ $\angle$$B$ + $\angle$$D$=${240}^{\circ }$
and $\angle$$B$ = $\angle$$D$
​​​​​​​$\Rightarrow$ $\angle$$B$ = $\angle$$D$ = ${120}^{\circ }$