Question

NEED GEO HELP URGENT?

Answer 1

Secant and tangent theorem: Square of measure of tangent is equal to the product of length of whole secant and length of exterior secant segment, i.e.

$\text{ tangent }^2=\text{whole secant}\cdot \text{exterior secant}$.

The whole secant wuth exterior secant 4 cm is 4+x cm. Tangent is 7 cm. Using previous theorem, you can get that

$7^2=(4+x)\cdot 4$.

Solve this equation:

$49=16+4x,\\ 4x=49-16,\\ 4x=33,\\ x=8.25\approx 8.3$ cm.

Answer: x=8.3 cm.