Answer:
Step-by-step explanation:
a^2 +b^2 =c^2
279^2 +440^2=521^2
77841 + 193600= 271441
271441= 271441
(I used the pythagorean theorem formula. I knew 521 was c because c is the hypotenuse, which is the longest side. The other two sides are interchangable.)
Hopefully this helps!