Hello, SarahGr!

A triangle had area of 21 cm² and two of its sides are 9 cm and 14cm long.

Find the possible measures of the angle formed by these sides?

I know the formula for the area of a triangle is ½abSin(C)

but i have no idea how to do this one.

The formula is: .

We are given: .

Plug them in! . . .

Then: .