Question

In the given figure, ABCD is a parallelogram in which $\angle DAB$ = 75${}^o$ and $\angle$DBC = 60${}^o$ then the measure of $\angle$BDC is equal to ?

• A. 75${}^o$
• B. 60${}^o$
• C. 45${}^o$
• D. 55${}^o$

Answer 1

Answer: (C)

45${}^o$

Opposite angles of parallelogram are equal.
$\angle DAB=\angle BCD={75}^o$ and $\angle DBC={60}^o$
$\angle BDC+\angle DBC+\angle BCD={180}^o$
$\angle BDC={180}^o-\angle DBC-\angle BCD={180}^o-{75}^o-{60}^o={45}^o$