In a circle, the number of radians is proportional to the relative length of the arc, in comparison to the radius. We have that if we denote by x the radians, the following proportionality holds, relating angles and lengths:
because the total of angles in radians is 2pi and the total circumference is 2pi times the radius. Hence, by solving for x we get: x=4/7=0.57 rad
We also have that the area is proportional to the angles. The total are is
. Hence, A=
because the total of angles in radians is 2pi and the total circumference is 2pi times the radius. Hence, by solving for x we get: x=4/7=0.57 rad
We also have that the area is proportional to the angles. The total are is