Question 963801
If a chord of a circle of the radius 5 cm. is a tangent to a circle of radius 3 cm., both the circle being cocentric, then the length of the chord is:
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draw this out as described, note the chord is 3 cm from the center, draw two 5" radii to each end of the chord, forming two right triangles.
Let a = half the length of the chord, use pythag here
a^2 + 3^2 = 5^2
a^2 = 25 - 9
a = {{{sqrt(16)}}}
a = 4"
therefore
2 * 4 = 8" is the length of the chord
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