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
