Please help me solve this :(

Question

If side P = 8cm, Q = 7cm and side R = 5cm. So the area of the triangle is?

Answer 1

For side-side-side situations, you can use Heron's formula:

Area = sqrt(S(S-P)(S-Q)(S-R))

where S = (P+Q+R)/2

Plug in P,Q,R to find S in the bottom equation, then compute and plug in the indicated difference values to the top equation to get Area = 17.32 cm²