Find the area of a triangle with sides of 12, 14 and 20
Use the Cosine Law to find the angle Ø opposite side 12 by
12^2 = 14^2 + 20^2 - 2(14)(20)cosØ
then use
Area = (1/2)(14)(20)sinØ
or you might want to Google "Heron's Formula"
it is an interesting method