PLEASE HELP ME WITH NUMBER 1

Answer:
[tex]a^{2}[/tex] + [tex]b^{2}[/tex] = [tex]c^{2}[/tex]
Step-by-step explanation:
Pythagorean Theorem
The proof is a little long, but you can check it out here:
https://www.mathsisfun.com/geometry/pythagorean-theorem-proof.html
Math is fun is a pretty useful website to help visualize mathematical concepts, enjoy!