Area of Circle (in terms of pi)

Area of Circle

(in terms of pi)

Area Given Radius

•  $A=\pi r^2$  

• Plug in radius

•  $A=\pi6^2$  

• Square the radius

•  $A=36\pi\ cm^2$  

Area Given Radius

•  $A=\pi r^2$  

• Plug in radius

•  $A=\pi5^2$  

• Square the radius

•  $A=25\pi\ cm^2$  

Area Given Radius

•  $A=\pi r^2$  

• Plug in radius

•  $A=\pi12^2$  

• Square the radius

•  $A=144\pi\ cm^2$  

Multiple Choice

What is the formula for areaof a circle given the radius?

• A = πr

• A = 2πr

• A = πd

• A = πr²

Multiple Choice

What is the area of the circle in the image?

• 10

• 20π

• 100

• 100π

Multiple Choice

What is the area of this circle?

• 4π

• 8π

• 16π

• π

Multiple Choice

Find the area of the circle in terms of π

• $8\pi\ cm^2$

• $64\pi\ cm^2$

• $16\pi\ cm^2$

• $4\pi\ cm^2$

Area given Diameter

• Divide the diameter by 2 to find the radius

• r=7 cm

• Plug radius into formula

•  $A=\pi7^2$  

• square the radius

•  $A=49\pi\ cm^2$  

Area given Diameter

• Divide the diameter by 2 to find the radius

• r=9 in

• Plug radius into formula

•  $A=\pi9^2$  

• square the radius

•  $A=81\pi\ in^2$  

Area given Diameter

• Divide the diameter by 2 to find the radius

• r=18 ft

• Plug radius into formula

•  $A=\pi18^2$  

• square the radius

•  $A=324\pi\ ft^2$  

Multiple Choice

What is the area of this circle?

• 16π cm²

• 8π cm²

• 4π cm²

• 16π² cm²

Multiple Choice

What is the area of the circle in the image?

• 9π

• 12π

• 12

• 36π

Multiple Choice

Find the area of the circle in terms of π

• $4\pi\ m^2$

• $16\pi\ m^2$

• $2\pi\ m^2$

• $8\pi\ m^2$

Multiple Choice

Find the exact area of a circle with diameter of 20 inches.

• 100 π in²

• 20 π in²

• 400 π in²

• 40 π in²