Circles
Vocabulary
Convert to a percent
Percent Calculation
Percent Increase/Decrease
100

What is the formula to find the circumference of a circle?

1) C= 2(pi)r

2) C= (pi)(d)

100

What is circumference? 

The distance around the outside of a circle.

100

Convert 0.25 to a percent

25%

100

What is 37% of 500?

185

100

Omar made $500 per day. He stopped showing up and got demoted to a job that paid $250. What was the percent change?

50% decrease.

200

If a circle has a diameter of 8cm, what is the radius?

r=4cm

200

What is a percent?

A ratio compared to 100.

200

Convert 0.8 to a percent

80%
200

What is 86% of 1,000?

860

200

Sam went from making $400 to $620. What was the percent change? Was it an increase or decrease?

Increase of 55%

300

Given a circle with a diameter of 10 ft. Calculate the circumference. Use 3.14 for the value of pi.

C=10pi

C=10(3.14)

C=31.4 ft

300

What is a radius?

A line segment with one end on the center of a circle and the other end somewhere on the circle.

300

Convert 1.34 to a percent

134%

300

What is 9% of 245?

22.05

300

Liam made $40 an hour. He received a 20% increase in pay. What does Liam make per hour now?

40 x 0.20 = 8

40+8=48

Liam makes 48 dollars an hour.

400

Given a circle with a radius of 3m, what is the circumference? Use 3.14 for the value of pi.

C=2(pi)r

C=2(pi)(3)

C=6pi

C=6(3.14)

C=18.84 m


400

What is a diameter?

A line segment that passes through the center and both ends lie somewhere on the circle.

400

Convert 2.568 to a percent

256.8%

400

What is 2% of 2,500?

50

400

Samantha found a dress that cost 80 dollars. She had a coupon and only payed 20 dollars. 

75% off 

20-80/80=0.75

500

The minute hand of a clock measures 12 inches. If one hour has passed what is the distance the minute hand of the clock traveled in total? Use 3.14 for the value of pi.

r=12in

C=2(pi)r

C=2(pi)(12)

C=24pi

C=24(3.14)

C=75.36 inches

500

How do we find percent change? (What is the formula)

(New Amount - Original Amount) / Original Amount

500

Convert 0.168436 to a percent.

16.8436%

500

What is 225% of 8?

18

500

What is Mr. Guzman's middle name

William