Answer:
3. 28 feet
4. 15
Explanation:
3. Using r for the radius of the pond, we have a right triangle with sides r and 45 ft, and hypotenuse (25+r) feet. The Pythagorean theorem tells us ...
(25+r)^2 = 45^2 +r^2
625 +50r +r^2 = 2025 +r^2
50r = 1400 . . . . . subtract 625+r^2
r = 28 . . . . . . . . . divide by 50
The radius of the pond is 28 feet.
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4. The marks on the chord segments tell us the chords are the same length. Same-length chords are the same distance from the center of the circle:
x = 15