Question

Solve for x, using the secant lines.

4 cm

1

20 cm

6 cm

x

X=[?] cm Remember : a • b = c • d

Answer 1

x = 10

Explanation:

given 2 secants from an external point to the circle, then

the product of the measures of one secant's external part and the entire secant is equal to the product of the other secant's external part and that entire secant, that is

6(6 + x) = 4(4 + 20)

6(6 + x) = 4 × 24 = 96 ( divide both parts by 6 )

6 + x = 16 ( subtract 6 from both sides )

x = 10