Circle Measurements Quiz

What is the diameter of the circle? d=7→r=3.5

• 7 cm

• 7.5 cm

• 3.5 cm

• 14 cm

Area of a circle formula: A=

π⋅16

• a= 3.5

• a = 77

• a= 14

• a= 256

How is the radius related to the diameter?

• Radius is three times the diameter

• Radius is equal to the diameter

• Radius is half the diameter

• Radius is twice the diameter

Area of a circle formula:

A, equals, pi, r, squared

A=πr2

• a = 99

• a= 144

• a= 14

• a= 175

Area of a circle formula:

A, equals, pi, r, squared

A=πr 5

• a= 3

• a = 7

• a = 14

• a= 25

Find radius from given diameter:

d, equals, 4, right arrow, r, equals, 2

• d= 4

• d= 8

• d= 6

• d=1

The radius of a circle is 13 in. Find its circumference in terms of piπ.

Visual representation:

Visual representation:

radius = 13 in

Circumference of a circle formula:

Circumference of a circle formula:

C, equals, 2, pi, r

C=2πr

2 times piπ times the radius

Substitute radius into formula:

Substitute radius into formula:

C, equals, 2, dot, pi, dot, 13

C=

2⋅π⋅13

C, equals, 2, dot, 13, dot, pi

C=

2⋅13⋅π

Commutative property of multiplication

C, equals, 26, pi

C=

26π

• TRUE

• FALSE

Circumference of a circle formula:

C, equals, 2, pi, r

C=2πr

2 times piπ times the radius

Substitute radius into formula:

Substitute radius into formula:

C, equals, 2, dot, pi, dot, 7

C=

2⋅π⋅7

C, equals, 2, dot, 7, dot, pi

C=

2⋅7⋅π

• c= 12

• c= 13

• c= 14

• c= 654312

redounding : Circumference of a circle formula:

C, equals, 2, pi, r

C=2πrC=

2⋅π⋅9

C, equals, 2, dot, 9, dot, pi

C=2⋅9⋅πC=18πC=56.54866776...

• 7743.9

• 32431

• 56.5

• 45.6

rounding: Substitute radius into formula:

C, equals, 2, dot, pi, dot, 3

C=

2⋅π⋅3

C, equals, 2, dot, 3, dot, pi

C=2⋅3⋅πC=6πC=18.84955592...

• 56.0

• 18.8

• 8765123.0

• 89.9