Question

please help! Find the perimeter of a sector of a circle with central angle 7π/4 and radius 3ft. I'm not sure what I'm supposed to add..

Answer 1

Your trying to find the perimeter of a wedge from a circle right?

Answer 2

The formula for circumference (i.e. perimeter) is the radius of a circle, times the angle.

For instance, C = 2π(r), where 2π is the entire 360 degrees of a circle and r is obviously the radius will find you the entire circumference of a circle.

If you only want to find a portion of the circumference, just change the angle

So, C = (7π/4)(3) <--- the equation of the circumfrence of the sector of your circle.

Now, if you are looking for the total perimeter of your sector, you need to add in both the lines that make up the arc, so it would be

P = (7π/4)(3) + 3 + 3

i'll draw a lil' pic

Answer 3

Good explanation. I learn something new today! thanks @funinabox