Question

In the given figure triangle ABC is circumscribed by a circle, AB =5 cm, $\angle A={30}^{\circ },\angle C={60}^{\circ }$.The length BC equal is to $[sin{60}^{\circ }=0.86,sin{30}^{\circ }=0.5]$

• A. 2.9 cm
• B. 4 cm
• C. 2.1 cm
• D. 3.5 cm

Answer 1

The correct option is A

2.9 cm

In the given triangle ABC, applying sine rule we have

$\frac{AB}{sin{60}^{\circ }}=\frac{BC}{sin{30}^{\circ }}$

$\frac{5}{0.86}=\frac{BC}{0.5}$

$BC=\frac{5\times 0.5}{0.86}=2.9cm$