trigonometry
posted by lindsay .
given triangle ABC with AB=7cm, BC=8cm and AC=9cm calculate
1. the size of the largest angle
2. the area of the triangle

1.
the largest angle is opposite the largest side, so set your cosine equation up this way:
9^2 = 7^2 + 8^2  2(7)(8)cosØ
2.
once you have that angles use the area formula
area = (1/2)(a)(b)sinØ , where Ø is the contained angle. 
Find the a triangle whose sides are 7cm,8cm,and 9cm