Perimeter/Area of Circles and SemiCircles

 What is the formula for circumference of a circle given the diameter?

• C = π r

• C = π d

• C = 2 π r

• C = 2 π d

Tags

CCSS.HSG.GMD.A.1

If you are given the diameter, how can you calculate the radius?

• Multiply the diameter by 2

• Subtract 2 from the diameter

• Add 2 to the diameter

• Divide the diameter by 2

How do you find the area of a circle?

• $\pi d^2$

• $2\pi r$

• $2\pi^2$

• $\pi r^2$

Tags

CCSS.HSG.GMD.A.1

A _____ is half of a circle.

• circumference

• pi

• semicircle

• composite figure

Steven purchases a bowl. The diameter of the

bowl is 14 cm. What is the circumference of the

bowl? Round to the nearest hundredth. Don't forget to label.

Tags

CCSS.HSG.GMD.A.1

Daniel wants to buy cookies for his friend. The

radius of a cookie is 5 inches. What is the cookie’s

circumference? Round to the nearest hundredth. Don't forget to label.

Tags

CCSS.HSG.GMD.A.1

Mrs. Wilson placed the welcome mat shown below on her front door step. What is the PERIMETER of her welcome mat in feet? Round to the nearest hundredth. Don't forget to label.

Tags

CCSS.HSG.GPE.B.7

What is the area of this circle?

• 6082.12
• 1519.76
• 1893.14
• 1292.92

Tags

CCSS.HSG.GMD.A.1

If you have been given diameter, how do you find radius?

• Radius times radius
• a.  Radius plus radius
• Diameter divided by 2

Find the area of this Semicircle with a diameter of 18 cm

• 254.34 cm
• 127.17 cm
• 56.52 cm
• 28.26 cm

Tags

CCSS.HSG.GMD.A.1