Question

Explain how to use a coordinate plane to find the area of a rectangle with vertices (–4, 9), (–4, –3), (–1, –3), and (–1, 9). what is the area?

Answer 1

Sample Response: Plot each point in the coordinate plane. Find the distance between points to find that the base is 3 units and the height is 12 units. Apply the area formula, A = bh. 3 x 12 = 36 square units.

Answer 2

the formula for area of a rectangle is

Area = length x width

since both the length and the width of the rectangle lie on the same x and y axis, we can find the distance between the width and the distance between the length by subtracting

(-4,9) (-4,-3)

these points lie on the same x axis, so they create a vertical line

9-(-3) = 12

12 units is the distance between them

(-4,-3) (-1,-3)

these points lie on the same y axis, so they create a horizontal line

-1-(-4) = 3

3 units is the distance between them

now that we have the length and the width, we can find the area

A = 12 x 3

A = 36 units²