Question

Solve For The Radius:

a. r = 9.7 m
b. r = 7 m
c. r = 123.5 m
d. r = 19.4 m

Answer 1

a) r = 9.7 m

Explanation:

CD = CE + ED

= 9 + r +r

= 9 + 2r

If a tangent and a secant are drawn from a common point outside the circle, then

CE * CD = CB *CB

9 * ( 9 + 2r) = 16 * 16 {Distributive property}

9*9 + 9*2r = 256

81 + 18r = 256

Subtract 81 from both sides,

18r = 256 - 81

18r = 175

Divide both sides by 18,

r = 175÷ 18

`\boxed{\bf r = 9.7 \ m }`