Answer:
A. 7 units
Step-by-step explanation:
The given triangle is a right-angled triangle.
This means that we can apply the Pythagorean theorem relating the lengths of the sides a follows:
(hypotenuse)² = (first side)² + (second side)²
In the given we have:
hypotenuse = 25 units
first side = 24 units
second side is the one we want to find
Substitute with the givens in the above equation to get the missing side as follows:
(25)² = (24)² + (second side)²
(second side)² = (25)² - (24)²
(second side)² = 49
either: second side = -√49 = -7 .......> rejected as side length cannot be negative
or: second side = +√49 = 7 .........> accepted
Hope this helps :)