Circumference: Calculate The Missing Side based on the formula

Increasing a specific element by addition of.....or multiplication by.......Using Pythagoras' theoremVerifying whether or not the formula is applicableSubtraction or addition to a larger shapeA shape consisting of several shapes (requiring the same formula)Using variablesCalculating parts of the circleIdentifying and defining elementsUsing additional geometric shapesWorded problemsIdentify the greater valueFinding Area based off Perimeter and Vice VersaApplying the formula
Question 1

A circle has a circumference of 31.41.

What is its radius?

Question 2

A circle has a circumference of 50.25.

What is its radius?

Question 3

The circumference of a circle is 14.

How long is the circle's radius?

Question 4

Calculate the radius based on the circumference given in the figure:

C=81C=81C=81

Question 5

Calculate the radius using the circumference given in the figure:

C=15.67C=15.67C=15.67

Examples with solutions for Circumference: Calculate The Missing Side based on the formula

Exercise #1

A circle has a circumference of 31.41.

What is its radius?

Video Solution

Step-by-Step Solution

To solve the exercise, first we must remember the circumference formula:

P=2πR P= 2\pi R

P is the circumference and Pi has a value of 3.14 (approximately).

We substitute in the known data:

31.41=2⋅3.141⋅R 31.41=2\cdot3.141\cdot R

Keep in mind that the result can be easily simplified using Pi:

31.413.141=2R \frac{31.41}{3.141}=2R

10=2R 10=2R

Finally, we simplify by 2:

5=R 5=R

Answer

5

Exercise #2

A circle has a circumference of 50.25.

What is its radius?

Video Solution

Step-by-Step Solution

We use the formula:

P=2πr P=2\pi r

We insert the known data into the formula:

50.25=3.14×2r 50.25=3.14\times2r

50.25=2×r×3.14 50.25=2\times r\times3.14

50.25=6.28r 50.25=6.28r

50.256.28=6.28r6.28 \frac{50.25}{6.28}=\frac{6.28r}{6.28}

r=8 r=8

Answer

8

Exercise #3

The circumference of a circle is 14.

How long is the circle's radius?

Video Solution

Step-by-Step Solution

We begin by using the formula:

P=2πr P=2\pi r

We then insert the given data into the formula:

14=2×π×r 14=2\times\pi\times r

Lastly we divide Pi by 2:

142π=2πr2π \frac{14}{2\pi}=\frac{2\pi r}{2\pi}

7π=r \frac{7}{\pi}=r

Answer

7π \frac{7}{\pi}

Exercise #4

Calculate the radius based on the circumference given in the figure:

C=81C=81C=81

Video Solution

Answer

12.891

Exercise #5

Calculate the radius using the circumference given in the figure:

C=15.67C=15.67C=15.67

Video Solution

Answer

7.269

Question 1

Calculate the radius using the circumference given in the figure:

C=35.6C=35.6C=35.6

Question 2

Calculate the radius using the circumference given in the figure:

C=400C=400C=400

Question 3

Calculate the radius using the circumference given in the figure:

C=80C=80C=80

Question 4

Calculate the radius using the circumference given in the figure:

C=9C=9C=9

Question 5

Calculate the radius using the circumference given in the figure:

Exercise #6

Calculate the radius using the circumference given in the figure:

C=35.6C=35.6C=35.6

Video Solution

Answer

5.666

Exercise #7

Calculate the radius using the circumference given in the figure:

C=400C=400C=400

Video Solution

Answer

63.662

Exercise #8

Calculate the radius using the circumference given in the figure:

C=80C=80C=80

Video Solution

Answer

12.732

Exercise #9

Calculate the radius using the circumference given in the figure:

C=9C=9C=9

Video Solution

Answer

1.432

Exercise #10

Calculate the radius using the circumference given in the figure:

Video Solution

Answer

0.009

Question 1

Given that the circumference of a circle is 20, what is the length of the circle's radius?

Question 2

If the circumference of a circle is equal to 18, then what is the length of its radius?

Question 3

Look at the circle in the figure.

What is its diameter?

Question 4

The circumference of a circle is 4.

How long is the radius of the circle?

Question 5

The circumference of a circle is 60.

What is the length of the radius of the circle?

Exercise #11

Given that the circumference of a circle is 20, what is the length of the circle's radius?

Video Solution

Answer

10π \frac{10}{\pi}

Exercise #12

If the circumference of a circle is equal to 18, then what is the length of its radius?

Video Solution

Answer

9π \frac{9}{\pi}

Exercise #13

Look at the circle in the figure.

What is its diameter?

Video Solution

Answer

16 16 cm

Exercise #14

The circumference of a circle is 4.

How long is the radius of the circle?

Video Solution

Answer

2π \frac{2}{\pi}

Exercise #15

The circumference of a circle is 60.

What is the length of the radius of the circle?

Video Solution

Answer

30π \frac{30}{\pi}

Question 1

The circumference of a circle is equal to 100. What is the length of the radius of the circle?

Question 2

The circumference of a circle is equal to 14. How long is the circle's diameter?

Question 3

The circumference of a circle is equal to 15.

What is the length of its diameter?

Question 4

The circumference of a circle is equal to 16.

What is the length of the circle's radius?

Question 5

The circumference of a circle is equal to 30.

What is the length of the circle's diameter?

Exercise #16

The circumference of a circle is equal to 100. What is the length of the radius of the circle?

Video Solution

Answer

50π \frac{50}{\pi}

Exercise #17

The circumference of a circle is equal to 14. How long is the circle's diameter?

Video Solution

Answer

14π \frac{14}{\pi}

Exercise #18

The circumference of a circle is equal to 15.

What is the length of its diameter?

Video Solution

Answer

15π \frac{15}{\pi}

Exercise #19

The circumference of a circle is equal to 16.

What is the length of the circle's radius?

Video Solution

Answer

8π \frac{8}{\pi}

Exercise #20

The circumference of a circle is equal to 30.

What is the length of the circle's diameter?

Video Solution

Answer

30π \frac{30}{\pi}