4.1- Investigating Circles
The diameter of a circle if it's radius is 5cm.
10cm
Describe/explain what the circumference of a circle is.
The perimeter or distance around the circle.
The base of a parallelogram is 5m, the height is 4m. What is the area of this parallelogram?
20m2
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
The box beside a circle graph/pie chart showing what category each sector represents is called what?
Legend
The radius of a circle if it's diameter is 26m.
13m
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.
The area of a parallelogram is 72m2. The height is 8m. What is the base of this parallelogram?
9m
The radius of a circle is 7in. What is the area of this circle?
153.86in2
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
The diameter of a circle if it's radius is 442km.
884km
If the diameter of a circle is 25in, then what is the circumference?
75in
The base of a triangle is 14cm, the height is 10cm. What is the area of this triangle?
70cm2
The diameter of a circle is 10ft. What is the area of this circle?
78.5ft2
A circle's central angles adds up to how many degrees?
360 degrees
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
If the radius of a circle is 13m, then what is the circumference of this circle?
78m
The area of a triangle is 25yd, the base is 5yd. What is the height of this triangle?
10yd
The circular vent on a furnace has diameter 19.4cm. What is the area of the vent?
295.44cm2
Find 25% of 360 degrees.
90 degrees
If you know the radius of a circle, what is the correct formula to determine the circle's diameter?
d= 2r
A string of length 18mm is bent to form a circle. What is the diameter AND radius of this circle?
D= 6mm, R= 3mm
The area of a triangle is 160in, the height is 20in. What is the base of this triangle?
16in
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
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