Question

For $\Delta ABC\cong \Delta DEF$. Then according to the given figure,$\angle D={40}^o$, $\angle C=$.....

• A. ${40}^o$
• B. ${90}^o$
• C. ${60}^o$
• D. ${50}^o$

Answer 1

The correct option is D ${50}^o$

According to the given figure,
$\angle B=\angle E={90}^o$
$\Rightarrow AC=DE=5$ cm (hypotenuse) and $BC=EF=2$ cm
$\therefore \Delta ABC\cong \Delta DEF$ ..... (R.H.S condition for congruence)
$\Rightarrow \angle A=\angle D={40}^o$
$\Rightarrow \angle B={90}^o$
$\angle C=?$
We know $\angle A+\angle B+\angle C={180}^o$
$\therefore \angle C={180}^o-{90}^o-{40}^o$
$\therefore \angle C={50}^o$