No its not because its a repeating decimal for a number to be a irrational number it has to be non terminating or non repeating
The cofunction of cos is sin(90-x)
90 degrees is equal to PI/2
The cofunction becomes sin(PI/2 - 2PI/9)
Rewrite both fractions to have a common denominator:
PI/2 = 9PI/18
2PI/9 = 4PI/18
Now you have sin(9PI/18 - 4PI/18)
Simplify:
Sin(5PI/18)
Work problems are solved by first figuring out how much of the job they can do in each hour. Shawn can do 1/4 of the job in an hour and Ellie can do 1/6 of the job in an hour. 1/6+1/4=2/12+3/12=5/12. This means that they can do 5/12 of the job an hour. This means that together they can do the job in 2 2/5 hours. The foreman is obviously wrong because first of all Shawn can do it alone in 4 hours, so with Ellie he will do it faster, and second of all 2 2/5<5. Hope this helped!
The area of the square is 81 sq in, and the area of the circule is (3.14)(3 in)^2, or approx 3.14(9) sq in, or approx 28.27 sq in.
Subtract: 81 sq in - 28.27 sq in = approx. 52.73 sq in.
The difference is 52.73 sq in; the square is larger, the circle smaller.