Area and Circumference of circles

What is the formula for area of a circle when you know the radius?

•  $\pi r^2$  
  

•  $\pi\left(\frac{d}{2}\right)^2$  
  

•  $2\pi r$  
  

•  $\pi d$  
  

Tags

CCSS.7.G.B.4

What is the radius of this circle?

• 12
• 6
• 24

Tags

CCSS.7.G.B.4

 $A=\pi\left(\frac{d}{2}\right)^2$  

What is the area of this circle?

• 163.2

• 15.3

• 124.2

• 113.1

Tags

CCSS.7.G.B.4

 $A=\pi r^2$  

What is the area of this circle?

• 1385.44

• 2142.12

• 5541.77

• 1289.12

Tags

CCSS.7.G.B.4

What is the radius of this circle?

• 20
• 10
• 40

Tags

CCSS.7.G.B.4

What is the area of this circle?

• 1256.64
• 31.41
• 314.16
• 123.12

Tags

CCSS.7.G.B.4

What is the area of this circle?

• 163.2
• 15.3
• 124.2
• 113.1

Tags

CCSS.7.G.B.4

What is the area of this circle?

• 1385.44
• 2142.12
• 5541.77
• 1289.12

Tags

CCSS.7.G.B.4

What is the radius of this circle?

• 20
• 10
• 40

Tags

CCSS.7.G.B.4

What is the area of this circle?

• 1256.64
• 31.41
• 314.16
• 123.12

Tags

CCSS.7.G.B.4