Answer:13.5 inches
Step-by-step explanation:
Given diagonal as 15.6inches
Width is unknown
Height is 7.8 inches
From the diagram attached it forms a right angle solved using Pythagoras theorem
Ie
15.6^2=width^2+7.8^2
Width= ✓(15.6^2-7.8^2)=13.5inches
The answer is the third one
The sum is 194. You would just add them all together.