Doug started his math homework at 7:55 P. M. He finished all the problems at 8:15 P. M. How long did Doug spend doing his math homework?

20 minutes

Step-by-step explanation:

If you add 20 minutes to 7:55 P.M., it becomes 8:15 P.M.

step-by-step explanation:

there is a formula i can give you:

it is r^2*n*sin(360/n) divided by 2 where r represents the "radius" and n is the number of sides.

plug them in:

(10sqrt(3))^2*6*sin(360/6) divided by 2

100*3*6*sin(60) divided by 2

900*sin(60)

900*sqrt(3)/2

450*sqrt(3)

approx is 779.4 cm^2