Question

In a $\Delta ABC,if\angle C={30}^{\circ },a=47cmandb=94cm$, then the triangle is

• A. Right angled
• B. Right angled isosceles
• C. Isosceles
• D. Obtuse angled

Answer 1

The correct option is D

Obtuse angled

$cosC=\frac{a^2+b^2-c^2}{2ab}$
$\Rightarrow \frac{\sqrt{3}}{2}=\frac{(47{)}^2+(94{)}^2-c^2}{2\times 47\times 94}\Rightarrow c=58.24$
$\angle B={124}^{\circ }$. Hence obtuse angled triangle.