im working with determinants can someone help me?

Here’s another way to do this. It’s a variation of Cramer’s rule. With this you don’t have to take the square root.

CPhill’s use of Heron's Formula is better because you are less likely to make a mistake.

Area of Triangle with vertices of A(-8,10) , B(6,17), C(2,-4)

Note that ABS is absolute value.

ABS(0.5[Xa(Yb –Yc) + Xb(Yc –Ya) + Xc(Ya –Yb) ])

ABS(0.5[-8(17-(-4)) + 6(-4-10) + 2(10-17))

ABS(0.5[8(21) + 6(-14) + (2(-7)])

ABS(0.5[-168 + (-84) + (-14)])

ABS(0.5[-266]

ABS( -133) = 133 acres

_7UP_

I, personally,  am not good with this,  but I am positive,  or almost positive,  that someone can help.

I don't know how to find this with determinants....but I can tell you how to solve it...

Find the distances between the three points. Label these a, b and c.

Find the semi-perimeter = (s) =  (a + b + c) / 2

The area is given by Heron's Formula =

A = √[ s * (s -a) * (s - b) * (s - c) ]