Given:
In a triangle, length of one side is 8 inches and length of another side is 12 inches, and an angle is a right angle.
To find:
The length of the missing side.
Solution:
In a right angle triangle,

Suppose the measures of sides adjacent to the right angle are 8 inches and 12 inches.
Substituting Perpendicular = 8 inches and Base = 12 inches, we get



Taking square root on both sides, we get



The length of the missing side is 14.4 inches. Therefore, the correct option is D.