Question 994568

a chord is 6 cm long. it is 15 cm from the centre of a circle. What is the radius of the circle.
<pre>The perpendicular bisector is drawn from the circle's center to the chord, which it bisects
We now draw 2 radii to each endpoint of the chord
We now have an isosceles triangle which consists of 2 right triangles, with 2 radii as its hypotenuses. 
To find the radius, we use the pythagorean theorem, and we get: {{{highlight_green(r^2 = 15^2 + 3^3)}}}. This results in a radius value of {{{highlight_green(r = sqrt(234))}}}