Question

Two circles,radii 7cm amd 2cm touch externally find the length of the common tangent

Answer 1

QUESTION :-

Two circles,radii 7cm amd 2cm touch externally find the length of the common tangent.

SOLUTION :-

=>Length of common tangent = √d² - (r1 - r2)²

=>Here, d = distance between centres of circle = 7 + 2 = 9cm.

=>And r1 = 7cm , r2 = 2cm.

=>Length of common tangent=√d²-(r1- r2)²

=>Length of common tangent=√9²-( 7- 2)²

=>Length of common tangent =√81 - (5)²

=>Length of common tangent=√81 - 25

=>Length of common tangent=√56

=> .°. Length of common tangent = 7.4cm.

Therefore, the length of common tangent is 7.4cm.