Question

Charles opened a door hinged at O by an angle of 45 degrees. The width of the door was 80 centimeters. Find the area swept by the door. Leave your answer in terms of pie

Answer 1

A=800πcm²

Explanation:

Knowing that the area of a circular sector is:

`A_(cs)=(\pi\alpha r^(2))/(360)`

where α is the sweep angle and r in the radio (according to the graph),

then

A=(45° π 80²)/360° = 800πcm²