Question

If the lengths of the sides of a triangle be $7,4\sqrt{3}and\sqrt{13}cm$, then the smallest angle is

• A. ${15}^{\circ }$
• B. ${30}^{\circ }$
• C. ${60}^{\circ }$
• D. ${45}^{\circ }$

Answer 1

The correct option is B

${30}^{\circ }$

$cos\theta =\frac{49+16.3-13}{\mathrm{2.7.4}\sqrt{3}}\Rightarrow \theta ={30}^{\circ }$