question_answer

The circum-radius of an equilateral triangle is 8 cm. The in radius of the triangle is

A) 3.25 cm

B)  3.50 cm

C)  4 cm

D)  4.25 cm

Correct Answer: C

Solution :

\[\because \]       \[\frac{OC}{OD}=\frac{2}{1}\]\[\Rightarrow \]\[\frac{8}{OD}=\frac{2}{1}\] \[\Rightarrow \]   \[OD=4\,\,\text{cm}\] In radius = 4 cm