Radius of a Circle Real World Problems

If the problem ask you to find the distance around a circle, which formula should you use?

(hint: circumference is the distance around a circle)

• r = d/2

• d = 2r

• C = πd

• A = πr²

If the word problem is asking you to find the space inside the circle, which formula should you use?

(hint: Area is the space inside a circle)

• r = d/2

• d = 2r

• C = πd

• A = πr²

Cynthia wants to buy a round photo frame for
her brother. The radius of the photo frame is 9 cm. 
What is the photo frame’s diameter?

• 28.26 cm
• 56.52 cm
• 4.5 cm
• 18 cm

A business has a circular lawn in front of the building (shown in the picture). It takes 75 steps to walk across the middle of the lawn. How many steps would it take to walk around the entire lawn? (Round your answer to the nearest whole number)

• 4,416 steps

• 118 steps

• 150 steps

• 236 steps

The Jones family wants to enclose their circular garden with a fence. What is the length of fencing they need to buy?

• 56.25 ft

• 246.2 ft

• 365.56 ft

• 392.5 ft

A circular race track has a radius of 0.5 miles. How far does a race car travel in one lap?

• 1 mile

• 0.25 miles

• 1.57 miles

• 15.7 miles

Five Italian chefs came together to bake the world’s largest pizza. Its diameter is 131 feet long! Which of these is closest to the area of the pizza?

• 13471 ft²

• 411 ft²

• 206 ft²

• 4290 ft²

Wheel has a circumference of 59.66 inches. What is the radius?

• 38 inches

• 9.5 inches

• 59.66 inches

• 119.32 inches

A bicycle tire has a diameter of 20 inches. How many inches is one full revolution of the wheel?  

• 31.4 in
• 1256 in
• 125.6 in
• 62.8 in

Hilary's Horse Hideaway is buying dirt to fill their circular training area. The training circle is 28 feet across. The dirt is sold in truckloads that cover 75 square feet of ground. How many truckloads of dirt will Hilary need?

• 8 truckloads

• 32 truckloads

• 33 truckloads

• 9 truckloads