Question

The vertices of a parallelogram are at (-9, 12), (-3, 12), (-5, 10), and (–11, 10). What is the perimeter of the parallelogram? Round your answer to the nearest whole number?

Answer 1

let point A has coordinates (-9;12),B(-3;12),C(-5;10) and D(-11;10).Then the vector AB={6;0}, BC={2;-2}, CD={6;0}, AD={2;-2} and their and the length of the vectors

`|AB| = |CD| = \sqrt{ {6}^(2) + {0}^(2) } = √(36) = 6 \\ |BC| = |AD| = \sqrt{ {2}^(2) + {( - 2)}^(2) } = √(8)`

`p = 6 + 6 + √(8) + √(8) = \\ = 12 + 2 √(8) = 17.66\approx18`