n = last test
(87 + 78 + 61 + n) : 4 = 78,5
87 + 78 + 61 + n = 78,5 x 4
n = 314 - 226
n = 88
The area of a sector of a circle can be calculated by using this formula:
A=(n/360)*pi*r^2
where n is the measure of the central angle of the sector in degrees. Since we are already given with the measurement of the central angle, we can substitute this to the above formula:
A=(30/360)*pi*r^2
Taking the value of pi as 3.14, then
A=(1/12)*3.14*r^2
A=0.2617*r^2
Just plug in the value of r. and you will get the area of the sector. Hope this helps!
Since only one person can finish in first place, one in second, etc., the total number of placers is 12x11x10, or 1320 different ways the 12 racers can finish 1st, 2nd and 3rd....
☺☺☺☺