Deck 30: Circumference of Circles, and Perimeter of Semicircular-Shaped Figures

Question 1

A semicircular-sided tank is welded in the shop. The length of the tank's bottom, shown in the figure, is 25", and the radius is 8". How long is the piece of metal used to form the sides of the tank, in inches? Round the answer to the nearest 1/16".

Answer 1

100 1/4

Question 2

A semicircular-sided tank is welded in the shop. The length of the tank's bottom, shown in the figure, is 20", and the radius is 5". How long is the piece of metal used to form the sides of the tank, in inches? Round the answer to the nearest 1/16".

Answer 2

71 6/16 or 71 3/8

Question 3

Using chalk and a rule, a circle with a diameter of 7" is marked on steel plate. How many inches does the chalk travel in drawing a complete circle? Give the answer to the nearest hundredth.

Answer 3

21.98

Question 4

What is the circumference of a circle with a radius of 4.6 cm? Round the answer, in cm, to the nearest hundredth.

Question 5

What is the circumference of the circle in inches if the diameter is 10"?

Question 6

What is the circumference of the circle in inches if the radius is 10 3/4"? Round the answer to the nearest 1/4".

Question 7

What is the circumference of the circle in inches if the radius is 10"?

Question 8

A semicircular object has a radius of 7.5". What is the distance around the object, in inches? Give the answer to the nearest hundredth.

Question 9

A semicircular-sided form is welded in a shop. Its two lengths are each 5.72 cm, while the radius forming the flat side of each semicircular end is 2.2 cm. What is the form's perimeter, in cm? Round the answer to the nearest hundredth.

Question 10

A semicircular-sided tank is welded in the shop. The length of the tank's bottom, shown in the figure, is 25", and the radius is 6". How long is the piece of metal used to form the sides of the tank, in inches? Round the answer to the nearest 1/16".