If two chords AB, CD intersect each other at O and AO = 9 cm, BO = 4 cm, CO = 10+x cm, DO = 10−x cm. Fine the value of x.
8
We know that
AO×BO=CO×DO
9×4=(10+x)×(10−x)
36=102−x2 ______ using formula (a+b)(a−b)=a2−b2
x2=100−36
x2=64
x=8, −8
Taking only positive value for length, we get x = 8 cm