Answer:
Explanation:
to prove it right angle
square of largst side must be eqaul to the sum of two other sides.
so here 12 is largest and 11 and 5 are two other smallest sides of a triangle.
(12)^2=(11)^2+(5)^2
144=121+25
144=146
since the square of largest side is not equal to the sum of square of other two smaller sides it can be concluded that the given sides of a triangle does not form a right angled triangle.