Can the numbers 24,32,40 be the lengths of three sides of a right triangle?

Yes

Step-by-step explanation:

using pythagorus theorum: a^{2} + b^{2} = c^{2}

24^{2} + 32^{2} = 1024+576

= 1600

40^{2} = 1600

thus, it can be concluded that these lengths can be the sides of a right-angled triangle.