Post a New Question


posted by .

An Equilateral triangle (ABC) is inscribed inside a circle. The side lengths of the triangle are 8 cm. What is the radius of the circle?

  • geometry -

    Let the triangle be named ABC.
    Name the centre of the circle O, and the mid-point of BC, D.
    Triangle ODC is a right-triangle, right-angled at D.
    radius, r = OC
    and OD=r/2 (∠OCD=30°).
    DC=8cm/2=4 cm.
    So all the sides ΔODC are known in terms of r.
    Use Pythagoras theorem to solve for r:

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

More Related Questions

Post a New Question