Answer: S - 10
Explanation:
The question states the 3rd side is 10cm less than the 2nd side. The keyword is less, less means subtract. Knowing we have to subtract we can eliminate the 3rd and 4th answer. Since the 2nd is equal to “s”, and the third side is 10cm less than the 2nd, the 3rd side must be equal to:
“s - 10”.