Circles Circles Circles

What number does the pi symbol represent?

Is the red line a radius or diameter of the circle?

• Radius
• Diameter

Tags

CCSS.HSG.C.A.2

Is the red line a radius or diameter of the circle?

• Radius
• Diameter

Tags

CCSS.HSG.C.A.2

Diameter = 40 ft.

Find the radius.

• 40ft

• 80ft

• 20ft

Radius = 15m

Find the diameter.

• 15m

• 30m

• 7.5m

What is the formula for finding the circumference of a circle?

• C = r²

• C = rd

• C = π·d

What is the formula for area of a circle?

• $A\ =\ \pi\ \times\ d$

• $A\ =\ 2\ \times\pi\times r$

• $A\ =\ \pi\times r^2$

Tags

CCSS.7.G.B.4

 $What\ does\ r^2\ represent?$  

•  $2\times r$  

•  $r\times r$ 

•  $\pi\times r$ 

Tags

CCSS.7.G.B.4

Find the circumference of the circle.

• 78.5 cm

• 15.7 cm

• 7.85 cm

Diameter = 14 cm.

Find the circumference.

• 38.47 cm

• 10.99 cm

• 43.96 cm