Question

An equilateral triangle ABC is inscribed in a circle centered at O and of radius 9 cm, as shown below. OD is a radius such that it is perpendicular to BC and cuts BC at point E. Then the length of OE is

• A. 4.5 cm
• B. 5 cm
• C. 5.5 cm
• D. 6 cm

Answer 1

The correct option is A

4.5 cm

Given, OD is a radius such that it is perpendicular to BC and OD = 9 cm.

We know that a side of an equilateral triangle drawn with vertices on a circle bisects the radius perpendicular to it.

So, the side BC of equilateral triangle ABC bisects the radius OD and hence OE = ED = $\frac{OD}{2}$ = 4.5 cm.