I need to know how to calculate what percentage of a number is to another.

let me make that clearer, 35 is what percent of 48? how is that calculated?

What you are asking is this:

35 is to 45 as x is to 100
or

35/48=x/100
solve for x
x=.729
Now to get % you must multiply x by 100 to get 72.9%

Plese try this link:
http://amby.com/educate/math/4-2_prop.html

Why is the theorem called the pythgorean Theream?

The Pythagorean Theorem is named after the ancient Greek mathematician Pythagoras, who is credited with its discovery. Pythagoras was an influential figure in the field of mathematics and is known for founding the Pythagorean school, which focused on geometric and numerical relationships.

The Pythagorean Theorem states that in a right-angled triangle, the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides. This fundamental relationship between the lengths of the sides of a right triangle has been widely used in various branches of mathematics and has significant practical applications in areas such as engineering, physics, and architecture.

Pythagoras is believed to have discovered and mathematically proven the theorem around the 6th century BCE. The theorem is credited to him due to his extensive work on geometry and his contributions to mathematical knowledge during that time.