# Perimeter, Circumference, and Area

## Presentation on theme: "Perimeter, Circumference, and Area"— Presentation transcript:

Perimeter, Circumference, and Area
Geometry Mrs. King Unit 1, Lesson 7

If we measured the perimeter, what would that look like? If we painted the floor, what geometry term are we measuring?

Definitions Perimeter: the sum of the lengths of the sides of a polygon Area: the number of square units a polygon encloses

Formulas

Find the perimeter and area of each figure:

Extension #1: Margaret’s garden is a square 12 ft on each side. Margaret wants a path 1 ft wide around the entire garden. What will the outside perimeter of the path be? Because the path is 1 ft wide, increase each side of the garden by 1 ft. s = = 14 P = 4s P = 4(14) = 56

Extension #2: Find the area of the figure below.
Step #1: Divide the figure into squares and rectangles: Step #2: Find each area. Then add the areas. AR = bh AR = (15)(5) AR = 75 AS = s2 AS = (5)2 AS = 25 A = A = 125

Formulas

Example: ⨀ G has a radius of 6.5 cm. Find the circumference of ⨀ G in terms of π. Then find the circumference to the nearest tenth. C = 2 π r C = 2 π (6.5) C = 13π C = ≈ 40.8

Example: Find the area of ⨀ B in terms of π. A = π r 2 A = π (1.5)2

Homework Perimeter, Circumference, and Area in Student Practice Packet
(Page 8, #1-16)