Question 160972
In a circle whose diameter is 20 inches, a chord is 6 inches from the center. What is the length of the chord?
:
Here is one way. Draw a circle, draw in the chord. See that a triangle is formed
by length of the chord  and two radii.
: 
This triangle consists of two right triangles where:
hypotenuse = 10" (radius)
one side = 6" distance from chord to the center
one side = 1/2 the length of the chord (x)
:
x^2 + 6^2 = 10^2
x^2 + 36 = 100
x^2 = 100 - 36
x = {{{sqrt(64)}}}
x = 8" is half the chord, therefore the chord = 16"