Answer:
x = 6.5 cm
Explanation:
The tangent to the circle forms a right angle with the radius x
Using Pythagoras' identity on the right triangle
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides
The hypotenuse is (x + 14.7) ← opposite the right angle, hence
(x + 14.7)² = x² + 20.2² ← expand parenthesis on left side
x² + 29.4x + 216.09 = x² + 408.04 ( subtract x² from both sides )
29.4x + 216.09 = 408.04 ( subtract 216.09 from both sides )
29.4x = 191.95 ( divide both sides by 29.4 )
x ≈ 6.5 cm