The definition of sin is the opposite/hypotnuse and since the hypotnuse has to be greater or equal to the other sides, the maximum possible value of sine is 1.
I believe the answer is B.)
If 
is the unknown concentration of the second solution, then each mL of this solution that is used in the new one contributes 
mL of acid.
There are 40 mL of the new solution, and one quarter is made up of 20% acid while the remaining three-quarters is made up of the solution - that is, 10 mL of a 20% acid solution are used, so that its contribution is 0.2(10 mL) = 2 mL of acid, while 30 mL of the solution are used, so it contributes 
of acid.
In this new solution, we want to get a concentration of 32% acid, so it should contain 0.32(40 mL) = 12.8 mL of acid. Then the total amount of acid in the new solution satisfies
so the second solution has a concentration of 36%. The equation used here is the same as the first choice (a),
If the length is w+4 then the equation for the whole perimeter would be 4w+8. 2w+8 for both of the lengths and 2w for both of the widths.
4w+8=48
4w+8-8=48-8
4w=40
4w/4=40/4
w=10
l=10+8, l=18
l x w=a, 18*10=180
The area of the rectangle is 180in^2
