Answer: 3 sqrt(21)
Explanation:
wow this problem is gross!
making the triangle,
you need to use the law of cosines! searching "law of cosines" online should help a lot!
c^2 = a^2 + b^2 − 2ab cos(C)
you know C = 60 degrees (from 12 pm to 2pm!)
a = 12 cm and b = 15 cm
plug it into the equation and you get
c = 3 * sqrt(21) = 13.748