Sector area = (central angle / 360) * PI * radius^2
sector area = (72 / 360) * PI * radius^2
radius^2 = sector area / [(72 / 360) * PI]
radius^2 = 16.2 * PI / [(1 / 5) * PI]
radius^2 = 16.2 / .2
radius^2 = 81
radius = 9
Source:
http://www.1728.org/radians.htm
The fraction of boys to total students would be 5/8
The fraction of boys to girls would be 5/3
It usually works well to do what the instructions tell you. Multiply each diameter by 3.14.
a) 3.14×6 cm = 18.84 cm
b) [can't read the picture]
d) 3.14×9 in = 28.26 in
e) 3.14×11 mm = 34.54 mm
Which one is the middle one ?
