Question

In a parallelogram ABCD, if $\angle A={45}^o$, then the other angles are __________.

• A. ${45}^o,{120}^o,{120}^o$
• B. ${45}^o,{135}^o,{135}^o$
• C. ${60}^o,{135}^o,{135}^o$
• D. ${60}^o,{120}^o,{120}^o$

Answer 1

Answer: (B)

${45}^o,{135}^o,{135}^o$

For a parallelogram $ABCD$

$\angle A=\angle C$

$\angle B=\angle D$

$\angle A+\angle B+\angle C+\angle D={360}^{\circ }$

$\angle A={45}^{\circ }$ (given)

$\angle C={45}^{\circ }$

$45+2\angle B+45=360$

$\angle B=\angle D={135}^o$