A circle has a center at (3,5) and passes through (0,2). What is the length of an arc covering 3π4 radians on the circle?

1 Answer
Mar 10, 2016

la=942π.

Explanation:

The radius of the circle with center in C(3,5) that passes through A(0,2) is the distance between the two points:

r=(xAxC)2+(yAyC)2=

=(03)2+(25)2=9+9=29=32.

The angle at the center of a circle is, obviously, 2π, so the angle of 34π is: 34π2π=38 of the whole circle.

Since the lenght of a circle is: lc=2πr=2π32=62π, then the lenght of the arc is:

la=62π38=942π.