Vocabulary
A straight line from the center to the circumference of a circle or sphere
Radius
What is the circumference of a circle if:
the radius = 7 yds?
43.96 yards
What is the formula to find the area of a circle?
A=
pir^2
What is the area of a circle if:
the Radius = 6 in
113.04 in2
What is the diameter of a circle whose circumference is 314?
100
Name the line in a circle that cuts it in half.
Diameter
A diameter goes across the circle passing through the middle.
What is the circumference of a circle if:
the radius = 9 yds?
56.52
What day is Pi Day?
March 14.
3/14
3.14 because the first digits of pi are 3.14
What is the area of a circle if:
the Radius = 3 ft
28.26 ft2
What is the diameter of a circle whose circumference is 690?
219.63
The outside measurement of a circle. Or the distance around the outside of the circle
Circumference
Circumference is the perimeter of a circle.
What is the circumference of a circle if:
the diameter is 16.8 yards?
52.75 yards
Find the area of a circle when the circumference is 28.26 feet.
63.59 ft2
What is the area of a circle if:
the Diameter = 12 feet?
113.04 ft2
What is the radius of a circle whose circumference is 901?
14.49
The measurement of the inside of a circle. Or how much the circle covers
Area
What is the circumference of a circle if:
the radius = 7.4 yds?
46.47 yds
What is the Area of a circle if the circumference is 43.96 cm?
153.86 cm squared
What is the area of a circle if:
the diameter = 8 in
50.24 in2
What is the radius of a circle whose circumference is 372?
59.24
What radius will make the circumference and area equal?
r = 2
Pi r ^ 2 = pi d diameter = 2r
Pi r^2 = pi 2 r divide both sides by pi
r^2 = 2r divide both sides by r.
r = 2
The circular fountain in front of the courthouse has a radius of 9.4 feet. What is the circumference of the fountain to the nearest hundredths?
59.03 ft
A rose garden is circular. The diameter of the garden is 18 feet. Find the total area of the garden using 3.14 for pi.
254.34 square feet
A dog is leashed to a point in the center of the back of my house, so the area the dog is able to explore is semi-circular. The leash is 20 feet long. What is the area of the region the dog can explore?
628 square feet
A circle is inside a square so that it touches all 4 sides in the center. The side length of the square is 8. What is the area of the part of the square that does not include the circle?
13.76