Please explain with solution Find the length of an are with

Please explain with solution

Find the length of an are with angle 90 degree in a circle with radius 10 miles. mi

length of arc with angle (in degrees), radius r is L =r(_/180^o)

given =90^o, r =10 miles

length of arc is L =10(90^o_/180^o)

length of arc is L =5 miles

length of arc is L =15.71 miles