What is the formula for the area of a circle?

The area is given by: $$A = \pi r^2$$ .

If a circle has a diameter of 12 inches, what is its circumference?

Circumference = $$C = \pi d = \pi \times 12 \approx 37.68 inches$$ .

What is the radius of a circle with an area of 50.24 cm²?

Radius = $$r = \sqrt{\frac{A}{\pi}} = \sqrt{\frac{50.24}{\pi}} \approx 4 cm$$ .

How do you find the diameter if you know the circumference?

Diameter = $$d = \frac{C}{\pi}$$ .

What is the circumference of a circle with a radius of 3 ft?

Circumference = $$C = 2\pi r = 2\pi \times 3 \approx 18.85 ft$$ .

If a penny has a radius of 9.5 mm, what is its diameter?

Diameter = $$d = 2r = 2 \times 9.5 = 19 mm$$ .

What is the area of a circle with a diameter of 10 m?

Area = $$A = \pi r^2 = \pi \left(\frac{10}{2}\right)^2 = \pi \times 25 \approx 78.54 m^2$$ .

If the radius of a circle is doubled, how does the area change?

The area increases by a factor of four: if radius is r, new area = $$A = \pi (2r)^2 = 4\pi r^2$$ .

Area and Circumference of Circles Flashcards

Student preview

15 questions

Show all answers

1.

FLASHCARD QUESTION

Front

What is the formula to find the radius of a circle if you know the diameter?

Back

2.

FLASHCARD QUESTION

Front

What is the relationship between radius and diameter?

Back

3.

FLASHCARD QUESTION

Front

What is the formula for the circumference of a circle?

Back

4.

FLASHCARD QUESTION

Front

If a circle has a radius of 10 cm, what is its diameter?

Back

5.

FLASHCARD QUESTION

Front

How do you calculate the circumference of a circle with a diameter of 14 m?

Back

6.

FLASHCARD QUESTION

Front

What is the area of a circle with a radius of 5 m?

Back

7.

FLASHCARD QUESTION

Front

If the circumference of a circle is 31.4 m, what is the radius?

Back

Access all questions and much more by creating a free account

Create resources

Host any resource

Get auto-graded reports

Continue with Google

Continue with Email

Continue with Classlink

Continue with Clever

or continue with

Microsoft

Apple

Others

Already have an account?

Similar Resources on Wayground

11 questions

Monomios e Polinomios

Flashcard

•

8th Grade

13 questions

Tell-Tale Heart | Chinook 8th Grade

Flashcard

•

8th Grade

10 questions

Noun suffixes -ness, -dom, -ship

Flashcard

•

7th - 8th Grade

10 questions

Reflexive Verbs in Spanish

Flashcard

•

9th Grade

15 questions

philippine history

Flashcard

•

8th Grade

14 questions

Malaysian History

Flashcard

•

7th Grade

15 questions

Math 7 3rd Nine Weeks Study Guide

Flashcard

•

6th - 8th Grade

15 questions

Bacteria

Flashcard

•

9th Grade

Popular Resources on Wayground

20 questions

"What is the question asking??" Grades 3-5

Quiz

•

1st - 5th Grade

20 questions

“What is the question asking??” Grades 6-8

Quiz

•

6th - 8th Grade

10 questions

Fire Safety Quiz

Quiz

•

12th Grade

20 questions

Equivalent Fractions

Quiz

•

3rd Grade

34 questions

STAAR Review 6th - 8th grade Reading Part 1

Quiz

•

6th - 8th Grade

20 questions

“What is the question asking??” English I-II

Quiz

•

9th - 12th Grade

20 questions

Main Idea and Details

Quiz

•

5th Grade

47 questions

8th Grade Reading STAAR Ultimate Review!

Quiz

•

8th Grade

Discover more resources for Mathematics

15 questions

Pythagorean Theorem Word Problems Quizizz

Quiz

•

8th Grade

20 questions

Graphing Inequalities on a Number Line

Quiz

•

6th - 9th Grade

20 questions

Scatter Plots and Line of Best Fit

Quiz

•

8th Grade

20 questions

Pythagorean Theorem Review

Quiz

•

8th Grade

15 questions

Combine Like Terms and Distributive Property

Quiz

•

8th - 9th Grade

20 questions

Function or Not a Function

Quiz

•

8th - 9th Grade

15 questions

8th U7 L10 - Representing Large Numbers on Number Line

Quiz

•

8th Grade

5 questions

8th U7 Topic 1 Quiz Review: Exponent Rules

Quiz

•

8th Grade