Thursday

March 5, 2015

March 5, 2015

Posted by **Katy** on Tuesday, March 29, 2011 at 10:48pm.

- geometry -
**MathMate**, Wednesday, March 30, 2011 at 9:14amLet 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:

(4cm)²+(r/2)²=r²

**Answer this Question**

**Related Questions**

geometry - Theres a circle with an equilateral triangle in the middle. The ...

geo - a graphic artist is using a coordinate plane to design a company logo. the...

math - An equilateral triangle is inscribed in a circle. The radius of the ...

Math - An equilateral triangle is inscribed in a circle. If the radius of the ...

geometry - an equilateral triangle of side 20cm is inscribed in a circle....

GEOMETRY CIRCLE - 1.An isosceles triangle with each leg measuring 13 cm is ...

GEOMETRY CIRCLES PLEASE - 1.An isosceles triangle with each leg measuring 13 cm ...

geometry - The radius of the inscribed circle is equal to twice the area of the ...

maths - 1.how many non congruent right triangles with positive integer leg ...

GEOMETRY CIRCLES - 1. Ab is a chord of a circle with center o and radius 52 cm...