1. Warm Up May 14th Fill in the blanks:
A rhombus has ____________________ diagonals.
A rectangle has ____________________ diagonals
A square has ___________________ and _________________ diagonals
Find the area of a trapezoid with bases of 4 and 17 and a height of 12.
How do you find slope? How do you find length?

2. Homework Questions?

3. Quiz Time!

4. Circles Circumference & Area

5. Parts of a Circle
Radius – distance from the center to any point on the circle.
Diameter – distance across
a circle through the center.
Equal to 2 times the
radius
radius
diameter
center

6. Formulas for Circles
π – Pi, Greek letter that represents a math constant and helps us find more information about circles
Circumference – distance
around a circle
C = πd or 2πr
Area – space enclosed by a
circle
A = πr2
radius
diameter
center

7. Examples
Find the circumference of each circle.
23 mm
4 cm

8. Examples
Find the circumference of each circle.
9 m
58 cm

9. Examples
Find the area of each circle.
9 m
58 cm

10. Examples
Find the area of each circle.
23 mm
4 cm

11. Examples
Find the area and perimeter of this shape.
13 cm
6 cm

12. Examples Find the radius of each circle.
Find the diameter & area Find the diameter &
circumference.
24 cm
Area = 24 ft2