Answer:
13cm
Step-by-step explanation:
Let the given lengths be the opposte amd adjacent sides of a right triangle'
The missing side will be the hypotenuse
Using the pythagoras theorem;
hyp^2 = 5² + 12²
hyp² = 25 + 144
hyp² = 169
hyp =√169
hyp = 13cm
Hence the missing one is 13cm