**Given circumference find radius worksheet : **

Worksheet on finding radius from circumference is much useful to the students who would like to practice solving problems on circles.

1. A circular pond has a circumference of 628 feet. A model boat is moving directly across the pond, along a radius, at a rate of 5 feet per second. How long does it take the boat to get from the edge of the pond to the center ?

2. The circumference of a car wheel is 62.8 inches. Find the diameter of the wheel.

3. The Ferris wheel can travel 2376 feet in one ride. If there are 12 revolutions in one ride, find the diameter of the wheel. Use π = 22/7.

**Problem 1 :**

A circular pond has a circumference of 628 feet. A model boat is moving directly across the pond, along a radius, at a rate of 5 feet per second. How long does it take the boat to get from the edge of the pond to the center ?

**Solution : **

**Step 1 : **

Find the radius of the pond.

Use the circumference formula.

C = 2πr

Substitute 628 for C and for 3.14 for π.

628 ≈ 2 x 3.14 x r

682 ≈ 6.28 x r

Divide both sides by 6.28

682/6.28 ≈ (6.28 x r)/6.28

100 ≈ r

The radius is about 100 feet.

**Step 2 :**

Find the time it takes the boat to get from the edge of the pond to the center along the radius.

Divide the radius of the pond by the speed of the model boat.

100 / 5 = 20

Hence, it takes the boat about 20 seconds to get to the center of the pond.

**Problem 2 :**

The circumference of a car wheel is 62.8 inches. Find the diameter of the wheel.

**Solution : **

Diameter = 2 x Radius

**Step 1 : **

Find the radius of the wheel.

Use the circumference formula.

C = 2πr

Substitute 62.8 for C and for 3.14 for π.

62.8 ≈ 2 x 3.14 x r

62.8 ≈ 6.28 x r

Divide both sides by 6.28

62.8/6.28 ≈ (6.28 x r)/6.28

10 ≈ r

The radius is about 10 inches.

**Step 2 :**

Multiply the radius by 2 to find diameter of the wheel.

10 x 2 = 20

Hence, diameter of the car wheel is about 20 inches.

**Problem 3 :**

The Ferris wheel can travel 2376 feet in one ride. If there are 12 revolutions in one ride, find the diameter of the wheel. Use π = 22/7.

**Solution : **

Diameter = 2 x Radius

**Step 1 :**

Find the radius of the wheel.

Distance traveled in one revolution is equal to circumference of the Ferris wheel.

Then the distance traveled in 12 revolutions (one ride) is equal to 12 times circumference of the Ferris wheel.

So, we have

2376 = 12C

Divide both sides by 12.

2376/12 = 12C/12

198 = C

Use the circumference formula.

C = 2πr

Substitute 198 for C and for 22/7 for π.

198 ≈ 2 x (22/7) x r

198 ≈ (44/7) x r

Multiply both sides by 7/44

(7/44) x 198 ≈ (7/44) x (44/7) x r

31.5 ≈ r

The radius is about 31.5 feet.

**Step 2 :**

Multiply the radius by 2 to find diameter of the wheel.

31.5 x 2 = 63

Hence, diameter of the Ferris wheel is about 63 feet.

After having gone through the stuff given above, we hope that the students would have understood "Given circumference find radius worksheet".

Apart from the stuff given above, if you want to know more about "Using circumference to find radius", please click here

Apart from the stuff given in this section, if you need any other stuff in math, please use our google custom search here.

HTML Comment Box is loading comments...

**WORD PROBLEMS**

**HCF and LCM word problems**

**Word problems on simple equations **

**Word problems on linear equations **

**Word problems on quadratic equations**

**Area and perimeter word problems**

**Word problems on direct variation and inverse variation **

**Word problems on comparing rates**

**Converting customary units word problems **

**Converting metric units word problems**

**Word problems on simple interest**

**Word problems on compound interest**

**Word problems on types of angles **

**Complementary and supplementary angles word problems**

**Markup and markdown word problems **

**Word problems on mixed fractrions**

**One step equation word problems**

**Linear inequalities word problems**

**Ratio and proportion word problems**

**Word problems on sets and venn diagrams**

**Pythagorean theorem word problems**

**Percent of a number word problems**

**Word problems on constant speed**

**Word problems on average speed **

**Word problems on sum of the angles of a triangle is 180 degree**

**OTHER TOPICS **

**Time, speed and distance shortcuts**

**Ratio and proportion shortcuts**

**Domain and range of rational functions**

**Domain and range of rational functions with holes**

**Graphing rational functions with holes**

**Converting repeating decimals in to fractions**

**Decimal representation of rational numbers**

**Finding square root using long division**

**L.C.M method to solve time and work problems**

**Translating the word problems in to algebraic expressions**

**Remainder when 2 power 256 is divided by 17**

**Remainder when 17 power 23 is divided by 16**

**Sum of all three digit numbers divisible by 6**

**Sum of all three digit numbers divisible by 7**

**Sum of all three digit numbers divisible by 8**

**Sum of all three digit numbers formed using 1, 3, 4**

**Sum of all three four digit numbers formed with non zero digits**