Vocabulary
What is the constant of proportionality between a circle's diameter and circumference?
Pi (3.14)
What is the radius of a circle with a diameter of 15?
The radius is 7.5
Marty McFly is crafting a pie. The pie has a diameter of 8.5 inches. What is the area of the pie?
The area of the pie is 56.71625
The line created when a plate is snapped in half
The diameter
What is the APPROXIMATE area of the state of New Mexico? (Draw on board)
Approximately 144,892
The _____ is a line segment that goes from one edge of the circle to the other, and passes through the origin.
What is the circumference of a circle with a radius of 2?
The circumference is 12.56
Patricia is prepping dough to make donuts. First, she outlines a circle to represent the donut, with a diameter of 8 inches. Then, she cuts a smaller circle out of the middle of the donut-circle, that has a diameter of 2 inches. What is the area of the donut once the donut hole is removed?
The area of the leftover donut is 47.1 inches
The length of a propeller blade on a helicopter
The radius
What is the EXACT area of the shape? (Draw on the board)
The area is 185.04
A _____ is a line segment that goes from the center to the edge of a circle.
Radius
What is the area of a half-circle with a radius of 3?
The area is 14.13
A bowling alley just ordered brand new bowling balls. The manager wants to order the bowling balls from biggest to smallest. Given the information below, order the bowling balls from biggest to smallest.
#1: Radius of 5 inches
#2: Diameter of 6 inches
#3: Circumference of 18 inches
#4: Radius of 2.5 inches
#5: Diameter of 9 inches
Order of biggest to smallest
#1 (31.4), #5(28.26), #2 (18.84), #3 (18), #4 (15.7)
The outline of a smiling face emoji
The circumference
What is the EXACT circumference of this shape? (Draw on the board)
The circumference is 26.69
_____ means 'to the second power'. It also represents when you multiply a number by itself.
Sqaured
What is the circumference of a quarter-circle with a radius of 4?
The circumference is 6.28
Tonya is throwing a hula hoop around that has a circumference of 52 inches. She throws the hula hoop 78 inches away from her. The hula hoop then travels back to her. How many total rotations did the hula hoop make?
The hula hoop made 3 total rotations
A circular fence surrounding a castle
The circumference
What is the EXACT area of this shape? (Draw on the board)
The area is 282.25
The units of a square with a side length of 5 feet would be 25 _______.
ft2 (feet squared)
What is the radius of a circle with an area of 314?
The radius is 10
An architect needs to fill in a swimming pool with water. The swimming pool has a diameter of 75 feet.
His supplier delivers trucks that can hold 100 gallons water at a time. 1 gallon of water can cover 5 square feet of area.
The architect will need 7 trucks.
The coffee inside of a circular mug
The area
What is the EXACT perimeter of this squircle?
The perimeter is 50.97