To use the Pythagorean theorem use the two smaller values and see if the formula equals the larder value. If it does it’s a right triangle if it doesn’t it is not a right triangle.
A. Sqrt(3.4^2 + 4.7^2) = 5.8
This is not a right triangle.
B. Sqrt(14.4^2 + 13^2) = 19.4
This is a right triangle.
C. Sqrt(12.5^2 + 4.5^2) = 13.28
This is not a right triangle.
D. Sqrt(0.3^2+1.4^2) = 1.437
This is not a right triangle.
The only one that is a right triangle is B.