work it out
how do you get the radius from the diameter
diameter divided by 2
What is the equation for circumference?
Two possible answers
2 x pi x r
or
pi x d
If the radius is 2cm, what is the area?
A = pi x r2
13cm2 (rounded)
Diameter of circle = 300 cm.
What is the radius?
150 cm
radius is half of the diameter
What/where is the radius on a circle? (write a definition)
A straight line that goes from the center of the circle to the edge of the circle.
How do you get the diameter from the radius?
radius x 2
If the circumference is 30km what would be the radius?
If C = pi x d
then r =
19km(rounded)
The diameter is 6 mm. What is the area?
28mm2 (rounded)
How do you get the radius when given the circumference?
C/pi/2
Circumference divided by pi divided by 2
What/where is the diameter? (write a definition)
Diameter is a straight line that goes through the middle of the circle and from one edge to the other edge.
83/pi=?
53 (rounded)
If the diameter of a pie is 15 in, what would the circumference be?
Use C=pi x d
47 inches (rounded)
If the diameter is 22km, what is the area?
380km2(rounded)
If the circumference is 32m, what is the radius?
radius = 5m (rounded)
What is circumference? (write a definition)
The circumference is the outside distance of a circle's edge (where you would build a fence around the outside)
Karen LOVES apple pie. She made the circumference 110 cm, but she needs to split it in half to share with one of her friends. What is the diameter?
Use the formula: C=pi x d OR C/pi
35cm
diameter = circumference / pi
If the radius is 65cm, then what is the circumference?
Use C = pi x d
hing: radius is half of diameter
408cm (rounded)
Sia knows the diameter of the circle is 60cm, but she needs help to get the area. What is it?
A = pi x r2
2827cm2 (rounded)
Circumference of a Circle =200cm
What is the radius?
C/pi = diameter
127cm (rounded)
What is area? (write a definition)
Area is the whole inside of the circle (think of laying a carpet).
Bethany's circle has a circumference of 103.50cm. She needs the diameter. What is it?
Use C = pi x diameter OR C/pi
33 (32.96)cm
Radius =1,110cm
What is the circumference?
C = pi x d
hint: radius is half the diameter
6981cm (rounded)
Radius = 65m
What is the area?
13273m2 (rounded)
Abigail has a circle with a circumference of 35.5in
What is the radius AND the area?
hint: use C = pi x d
radius = half of the diameter
Abigail's circle has a radius of 26.6in
and an area of 2222.86in2
BONUS: What day is June the last day of school for Grade 9s?
_______________, June _____, 2026
Tuesday, June 23, 2026