Circle Area and Circumference Exact Form

Which of the following below must you always use Pi calculations for?

• to find the area and circumference of a circle

• to find the area of a rectangle

• to find the height of a square

• to find the length from one edge of a triangle to another

• to find the derivative of a function

_____________ is the distance around the circle.

• circumference

• center

• radius

• diameter

• perimeter

Find the circumference of the circle shown. (HINT: Circumference = 2πr)

• 9π in.

• 4.5π in.

• 81π in.

• 28.26π in.

• 18π in.

Find the area of the circle shown. (HINT: Area = πr²)

• 11π m²

• 22π m²

• 121π m²

• 144π m²

• 484π m²

If the diameter of a circle is 50 yards, the radius is _____

• 100 yards

• 25 yards

• 150 yards

• 15 yards

• 50 yards

is twice the length of the radius.

• circumference

• center

• segment

• diameter

• chord

Pi is the ratio of a circle’s _________ to _________.

• radius / diameter

• circumference / diameter

• area / circumference

• circumference / radius

• diameter / radius

What is the circumference of this circle? Your answer will be in exact form.

What is the circumference of this circle? Your answer will be in exact form.

In the equation (x+2)²+(y-3)²=4, the radius of the circle is...

• 16

• 2