1. Perimeter, Circumference, and Area Learning Target: I can find the perimeter, circumference, and area of basic shapes.

2. The perimeter of a polygon is the sum of the lengths of its sides. The area of a polygon is the number of square units it encloses. The perimeter of a circle is called its circumference.

3. How could we find the area and perimeter of a square? Area:s 2 Peri meter: 4s s s

4. How could we find the area and perimeter of a triangle? Area: (1/2)bh Perimeter:add the sides together base (b) height (h)

5. How could we find the area and perimeter of a rectangle? Area: lw Perimeter: 2l+2w lenght (l) width (w)

6. How could we find the area and circumference of a circle? Area: πr 2 Circ umference: 2rπ radius (r) Remember diameter=2 radius

7. Finding Circumference What is the circumference of the circle in terms of π? What is the circumference of the circle to the nearest tenth? 15 in diameter=15, so radius=7.5 circumference=2rπ=2(15)π=30π

8. Try these: What is the circumference of a circle with radius 24 m in terms of π? circumference=2rπ=2(24)π=48π What is the circumference of a circle with diameter 24 to the nearest tenth? circumference=2rπ=2(12)π=24(3.14)=75.4

9. What is the area of the figure? All angles are right angles. 3 cm 9 cm You can cut the picture into 6 congruent squares. Area of one square is (6)(6)=36. Since there are 6 squares (6)(36)=216

10. What is the area of the figure? All angles are right angles. 4 ft 12 ft Cut the figure into a triangle on top and rectangle on bottom. Area of the triangle is (1/2)(8)(4)=16 Area of the rectangle is (4)(12)=48 16+48=64