8.1
Exercises
Help with
Bigideos
Vocabulary and Concept Check
1. VOCABULARY What is the relationship between the radius and the diameter
of a circle?
2. WHICH ONE DOESN'T BELONG? Which phrase does not belong with the other
three? Explain your reasoning
the distance around a circle times twice the radius
Umes the diameter
the distance from the center to any point on the circle
Practice and Problem Solving
Find the radius of the button.
28 mm
15 cm
YOUR
VOTE
COUNTS
Find the diameter of the object.
0.8
for.
Find the circumference of the pizza. Use 3.14
39.
17 in
10 in
18 in
CuOSE TOOLS Choose a real-life circular object Explain why you might need to