Circle Day

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

• C = r²

• C = rd

• A = π·r²

• C = π·d

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

• A = π·d

• C = 2·π·r

• A = π·r²

• C = π·d

Find the area of the circle.

• 18.84 m²

• 113.04 m²

• 37.68 m²

• 452.16 m²

What is the "formal" definition of pi?

• 22/7

• 3.1415926

• the ratio of a circle's circumference to its diameter

• the surface area of a sphere of diameter 22/7

Match the following vocabulary term with its appropriate part of the circle.

• Semi-Circle

• Point V

• Point of Tangency

• Major Arc

• Line PR

• Secant Line

• Minor Arc

Match the following

• Semi Circle

• Chord

• Secant

• Central Angle

• Point of Tangency

What is pi used to find? 

• the perimeter of a square

• the area of a rectangle

• radius of a circle

• circumference of a circle

What do you get when you divide the circumference of a Jack-o-Lantern by its diameter?

• Pumpkin

• Jack-o-Lantern

• Pumpkin Pi

• Pi in the Sky

What is the formal definition of pi? 

• The ratio of a circle's circumference to  its diameter

• 3.14159

• The radius of a unit circle

• The ratio of a circles diameter to its area

Does this picture show the diameter or radius of a circle?

• Diameter

• Radius