Finding surface area of a circle after removing a 36-degree sector

[mitz_fitz]

if some people could please allow me to bounce answers off them and show them my work by means of e-mail before I send it away to be marked, it would be highly appreciated, thanks

one problem I have at the moment is I need to find the surface area of a circle after a sector has been removed
the circle has a radius of 750mm and the segment is 36 degrees wide at the edge of the circle

thanks,
reuben

contact me directly mitz_fitz@hotmail.com

 

[whozum]

Removing a sector of a circle with an arc of 36 degrees gives 9/10 the area of the full circle. 36 degrees is (360-36)/360 = 324/360 = 9/10. Thus the net area is

$$\pi r^2 - \frac{\pi}{10} r^2$$ with r = 750mm.