f(2.5) means x is equal to 2.5.
Replace x in the equation with 2.5 and solve:
6(2.5) + 1.5 = 15 + 1.5 = 16.5
f(2.5) = 16.5
given ,
a circle of radius 12 inches
and
= 45°
now we know that ,

let's now plug in the values of radius and theta as 12 inches and 45° respectively ,

hope helpful :D
1 gallon (it’s stayed in the question)
It depends on how you count them. If you describe them by their dimensions, lowest one first, you can have
1 x 1 x 18
1 x 2 x 9
1 x 3 x 6
2 x 3 x 3
Of course, these dimensions can be put in any order.