What is the minimum cuts needed to cut a circle into 8 equal parts ?
A : 4 cuts
1.3*3=3.90
3.90*35=136.50
136.50 is all you need to provide at least three of the most expensive items.
You still have 13.50 left over
By induction:
It's true for

, since

clearly contains a factor of 3.
Suppose it's true for

, that

is divisible by 3. Then

where

is an integer. This reduces to

and both terms are clearly multiples of 3. We know that

is an integer since we had set

previously, which implies

is a multiple of

. So the statement is true.
The general rule for rotation of an object 90 degrees is (x, y) --------> (-y, x). You can use this rule to rotate a pre-image by taking the points of each vertex, translating them according to the rule, and drawing the image