Question

Find the perimeter of the triangle whose vertices are (−1,−4) , (15,8) , and (10,−4)

Answer 1

We call A(-1,-4); B(15,8); C(10,-4)

We have the formula to calculate AB:
AB = sqr[(-1-15)^2 + (-4-8)^2] = 20
BC = sqr[(15-10)^2 + (8+4)^2] = 13
AC = sqr[(-1-10)^2 + (-4+4)^2] = 11

So that, we can calculate perimeter of this triangle:
AB + BC + AC = 44