the angle = 144 degrees.
look at it this way (it is a proportion question)
30 people would require a pie chart made of a full circle (360 degrees)
12 people would require x part of the pie chart.
30/360 = 12 / x cross multiply
30x = 360 * 12 simplify the right
30x = 4320 divide by 30
30x/30 = 4320/20
x = 144 answer
write down the equation for calculating the volume of a sphere. this is the equation: v = ⁴⁄₃πr³.
find the radius. if you're given the radius, then you can move on to the next step.
cube the radius.
multiply the cubed radius by 4/3.
multiply the equation by π.