Question

Find the area of rectangle ABCD

Answer 1

Find the length of the rectangle with pythagoras
You can use point (0,0) and (3,3) as the reference points.
l = √(Δx² + Δy²)
l = √((3-0)² + (3-0)²)
l = √(3² + 3²)
l = √18

Find the width of the rectangle with pythagoras
You can use point (0,0) and (2,-2) as the reference points.
w = √(Δx² + Δy²)
w = √((-2-0)² + (2-0)²)
w = √((-2)² + 2²)
w = √(4 + 4)
w = √8

Find the area of rectangle
A = l × w
A = √18 × √8
A = √9 × √2 × √4 × √2
A = 3 × √2 × 2 × √2
A = 12

The area of the rectangle is 12 unit length