1. Do - Now
Find the circumference of the following circles: (Round answer to the nearest tenth.) 6 13 1 2
C = 40.8 units
C = 37.7 units
Find the area of the following circles: Round to the nearest tenth: 3 4
Leave in terms of : 4
A = 50.3 square units 14
A = 49 square units

2. Remember: Circumference: C = 2r or C = d Area: A = r2
1) The area of a circle is given as 49. What is the circumference of the circle in terms of ?
Area =  sq. units
2) The diameter of a circle is 15. What is the area in terms of ?
Circumference = 14  units

3. Answer: No, it will not be large enough.
Ed and Carol are jogging around a circular track in the park.  The diameter of the track is 0.8 miles.  Find to the nearest mile, the number of miles they jogged if they made two complete trips around the track.
Answer: 5 miles
Skeeter, the wonder dog, jumps through circular rings as part of his dog show exhibition.  Skeeter requires a width of 18 inches for his costume to clear the ring.  Will a ring with an inner circumference of 39.8 inches be large enough for Skeeter's act? 
Answer: No, it will not be large enough.

4. More multi-step problems:
A semi-circle drawn on a play ground needs to be repainted. The diameter of the semi-circle is 110 ft.
a) Find the area of the semi-circle.
Area of full circle: ft2
Area of semi-circle is half of area of full circle: Area of semi-circle = ft2
b) If each gallon of paint covers 450 square feet, how many gallons
Would be needed to cover the semi – circle?
Take the area of semi circle and divide by the amount of square feet each gallon will cover.
Answer = / 450  …
So 11 gallons will be needed.

5. Now, find area of just the fountain.
2) A sidewalk is to be place around a circular fountain whose diameter is 34 feet. The width of the sidewalk is 5 ft. A contractor will charge $2.34 per sq. ft. to construct the sidewalk. What will be the cost to construct the side walk?
First find area of whole circle (fountain & sidewalk).
So radius is half of 34 which is 17, plus 5ft from sidewalk, so radius of whole circle is 22ft. 34 5
A = r2 A = 222 = 484
A = 172 A = 289
Now, find area of just the fountain.
Now, take area of whole circle & subtract fountain, to find area of sidewalk.
Now find cost: 195 multiplied by $2.34 =
$ total cost
A = 484 - 289 = 195