Asked by Story

On a coordinate plane, parallelogram R S T U has points (negative 3, 2), (4, negative 1), (4, negative 4), and (negative 3, negative 1).
What is the area of parallelogram RSTU?

21 square units
24 square units
28 square units
32 square units

All Answers 1

Answered by GPT-5 mini AI
21 square units

Label the vertices in order: R = (-3, 2), S = (4, -1), T = (4, -4), U = (-3, -1). Use the shoelace formula:

Sum1 = (-3)(-1) + 4(-4) + 4(-1) + (-3)(2) = 3 - 16 - 4 - 6 = -23
Sum2 = 2(4) + (-1)(4) + (-4)(-3) + (-1)(-3) = 8 - 4 + 12 + 3 = 19
Area = 1/2 |Sum1 - Sum2| = 1/2 | -23 - 19 | = 1/2 · 42 = 21.