Circles & Area

4.1- Investigating Circles

100

The diameter of a circle if it's radius is 5cm. 

10cm

200

The radius of a circle if it's diameter is 26m.

13m

300

The diameter of a circle if it's radius is 442km.

884km

400

The merry-go-round on a school playground measures 3.5m from the center to the edge. What is the diameter of the merry-go-round?

7m

500

If you know the radius of a circle, what is the correct formula to determine the circle's diameter?

d= 2r

4.2- Circumference of a Circle

100

Describe/explain what the circumference of a circle is.

The perimeter or distance around the circle.

200

Explain the pattern/answer of a circle when you calculate the circumference divided by the diameter. 

The circumference divided by the diameter is approximately 3 each time.

300

If the diameter of a circle is 25in, then what is the circumference?

75in

400

If the radius of a circle is 13m, then what is the circumference of this circle?

78m

500

A string of length 18mm is bent to form a circle. What is the diameter AND radius of this circle?

D= 6mm, R= 3mm

4.3/4.4Area of a Parallelogram and Triangle

100

The base of a parallelogram is 5m, the height is 4m. What is the area of this parallelogram?

20m²

200

The area of a parallelogram is 72m². The height is 8m. What is the base of this parallelogram?

9m

300

The base of a triangle is 14cm, the height is 10cm. What is the area of this triangle?

70cm²

400

The area of a triangle is 25yd, the base is 5yd. What is the height of this triangle?

10yd

500

The area of a triangle is 160in, the height is 20in. What is the base of this triangle?

16in

4.5- Area of a Circle

100

What is the formula to find the area of a circle?

Area of a circle = pi (3.14)r²

^{OR 3.14 x r x r}

200

The radius of a circle is 7in. What is the area of this circle?

153.86in²

300

The diameter of a circle is 10ft. What is the area of this circle?

78.5ft²

400

The circular vent on a furnace has diameter 19.4cm. What is the area of the vent?

295.44cm²

500

In a composite figure, there is a rectangle that has a length of 11cm and a width of 4cm. There is also a square that has a length and width of both 5cm. What is the total area of this composite figure?

44cm² + 25cm² = 69cm²

4.6/4.7- Circle Graphs

100

The box beside a circle graph/pie chart showing what category each sector represents is called what?

Legend

200

In a circle graph, if heating is 29% of the energy bill, how much of the $2200 is spent on heating?

0.29 x 2200 = $638

300

A circle's central angles adds up to how many degrees?

360 degrees

400

Find 25% of 360 degrees.

90 degrees

500

In a survey, 2/27 people said that they liked Social Studies as their favorite subject. What is this number as a decimal, percent and angle in degrees?

0.07, 7%, 25.2 degrees