If the lengths of the three sides of △ ABC are M2-1, 2m, M2 + 1 (M > 1), then the degree of the largest angle is______ .

If the lengths of the three sides of △ ABC are M2-1, 2m, M2 + 1 (M > 1), then the degree of the largest angle is______ .

∵ (M2-1) 2 + (2m) 2 = m4-2m2 + 1 + 4m2 = M4 + 2M2 + 1, (M2 + 1) 2 = M4 + 2M2 + 1, ∵ (M2-1) 2 + (2m) 2 = (M2 + 1) 2, ∵ this triangle is a right triangle, and the degree of the largest angle is 90 degrees