Answer:
ED = 4 cm
Explanation:
given 2 secants from an external point to the circle, then the product 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
CD × CE = CB × CA
8(8 + x) = 6(6 + 10) = 6 × 16 = 96 ( divide both sides by 8 )
8 + x = 12 ( subtract 8 from both sides )
x = ED = 4 cm