Question 2522
In a right angled triangle let the perpendicular length be p and base be b and hypotenuse be h

In a right angles triangle hypotonuese is the longest side and also
p^2 + b^2 = h^2.

SO in a traingle with sides 10, 22 and 18......the longest side 22 be the hypotenuese
so let h = 22 
Now if (10)^2 + 18^2 = 22^2 then it will be a right angled triangle...
10^2 + 18^2 = 100 + 324 = 424

and

22^2 = 22*22 = 424

This implies that it is a right angled triangle :-)