This is the answer to a problem or an equation

Suppose a triangle has two sides of length 32 and 35, and that the angle between these two sides is 120°. which equation should you solve to find the length of the third side of the triangle?

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

The center of the circumscribed circle lies on line segment and the longest side of the triangle is equal to the of the circle.