Answer:
distance from the base where string is attached = 18.97 feet
Explanation:
The diagram attached to this solution gives a right-angled triangle formed by attaching the string to the top of the mast. the distance from the base is calculated as follows:
(hypotenuse)² = (opposite)² + (adjacent)²
23² = 13² + d²
529 = 169 + d²
d² = 529 - 169
d² = 360
d = √(360)
d = 18.97 feet