Perimeter and Area in the CoordinatePlane9-4

LESSON

Copyright by Holt, Rinehart and Winston. 197 GeometryAll rights reserved.

Lesson Objectives (p. 616):

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Key Concepts

1. Get Organized Complete the graphic organizer by writing the steps used tofind the area of the parallelogram. (p. 619).

Finding the Area

By subtracting:By using the formula:

4

23 0

y

x

Perimeter and Area in the CoordinatePlane9-4

LESSON

Copyright by Holt, Rinehart and Winston. 197 GeometryAll rights reserved.

Lesson Objectives (p. 616):

______________________________________________________________

______________________________________________________________

Key Concepts

1. Get Organized Complete the graphic organizer by writing the steps used tofind the area of the parallelogram. (p. 619).

find the perimeters and areas of figures in a coordinate plane.

Finding the Area

By subtracting:By using the formula:Draw a rectangle with an area of72 units2 around the figure.Subtract the areas of the trianglesin the corners: A = 72 (9)(2) (8)(3) (9)(2) (8)(3) = 30 units2.

12

12

12

12

4

23 0

y

x

The base of the parallelogram is35 units, and the height is 25units, so the area is A (35)(25) 30 units2.