Parts of a Circle
What is the outside length of a circle called?
circumference
If the radius is 4cm, what is the diameter?
8cm
What is the formula of circumference?
d x 3.14
The length of the line from the centre point to any point on the circumference is called a?
radius
If the diameter is 15cm, what is the radius?
7.5cm
If I only know the radius of a circle, how would I calculate the circumference?
d = r x 2
Describe an arc.
A portion of the circumference.
360 degrees
What is the circumference of the circle of diameter 2cm?
6.28cm
Describe what a diameter is to a person who has never heard of one before.
a line from one point on the circumference to another that goes through the centre point.
How many circles can I fit into a box in a row if the box' length is 20cm and the circles radius is 5cm?
2
I know the circumference of a circle. How would I calculate the diameter?
c divided by diameter
What parts of a circle must a sector include?
2 radii and an arc.
What size of a rectangle would I need (length and width) if I wanted to fit 3 circles of 2cm radius each in it?
(2 + 2) + (2 + 2) + (2 + 2) = 12
(2+ 2) = 4
Box = 12cm x 4cm
I know the circumference of a circle. How do I work out the radius of that circle?
c divided by d. Answer divided by 2.