Question

Can you pls tell me the answer

Answer 1

To find if it’s a right-angled triangle, we will have to use Pythagorean Theorem:
a² + b² = c²

1st triangle: (yes, it is)
40 ² + 30 ² = 50 ²

1600 + 900 = 2500

2500 = 2500


2nd triangle: (No)
15 ² + 21 ² = 26 ²

666 = 676


3rd triangle: (Yes)
1.8 ² + 8 ² = 8.2 ²

67.24 = 67.24


4th triangle: (No)
85 ² + 85 ² = 121 ²

14450 = 14641