A high fountain of water is located at the center of a circular pool as in Figure P1.61. Not wishing to get his feet
wet, a student walks around the pool and measures its
circumference to be 15.0 m. Next, the student stands at
the edge of the pool and uses a protractor to gauge the
angle of elevation of the top of the fountain to be 55.0°.
How high is the fountain?

Use photo math it it’s so good

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.