Answer:
12 units
Explanation:
To find any side length of a right triangle given two side lengths, you would use the pythagorean theorem which is a² + b² = c². In this equation, a and b represents either the height of base of the triangle, and c represents the hypotenuse of the triangle (the diagonal line - in your question it is 13). By plugging in the base and hypotenuse, you get the equation of 5² + b² = 13². 5² is equal to 25 and 13² is equal to 169, so the equation is 25 + b² = 169. Subtract 25 for both sides of the equation and you find that b² = 144. Square both sides and the missing length is 12 because √144 = 12.