Steps:
1. Let the three points be as follows:
A(-2,1), B(2,1), C(3,4)
2. Use the distance formula for points to find the lengths AB, BC, and AC. You will need to use the formula 3 times.
3. Use Heron's formula
A = sqrt{s(s-AB)(s-BC)(A-AC)}
Note s = (AB + BC + AC)/2
GET STARTED NOW.