Question

What is the area of this triangle?

Answer 1

area = 1/2 * base * height

base = the vertical line form (x1 y2) to (x1 y1) =  6 units

height = horizontal line from the vertical line to point (x3 y3) =  7 units

So area of triangle = 1/2 * 6 * 7 = 21 sq units