Answer: 75pi/2 square meters
This is the same as saying (75/2)pi and it is equivalent to 37.5pi
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Step-by-step explanation
diameter = 20
radius = diameter/2 = 20/2 = 10 meters
A full circle of radius 10 has area of
A = pi*r^2
A = pi*10^2
A = 100pi
The entire circle has area of exactly 100pi square meters.
But we only want a fractional pizza slice of this circle.
a 135 degree arc is 135/360 = 3/8 of a circle, so we want 3/8 of the full circle area.
3/8 of 100pi = (3/8)*100pi = 75pi/2 = 37.5pi