Answer:
19.5 inches
Step-by-step explanation:
See attachment for the figure, where two diagonals are added with labels.
Given:
length of BC 'b'= 7.5 inches
length of AC 'a'= 18 inches
Required:
length of diagonal= length of BA=?
Also, angle BCA is forming a right angle triangle. So we'll apply the Pythagoras theorem in order to find hypotenuse 'c' i.e the length of BA
c = √a²+b² => √7.5²+18²
c= 19.5
Therefore, the length of a diagonal of the box is 19.5 inches
