Question

The diagonal measure of a rectangular T.V screen is 42 inches. The width of the screen is 36.6 inches

Answer 1

A^2 + b^2 = c^2
The diagonal is the hypotenuse (c).
36.6^2 + b^2 = 42^2
1339.56 + b^2 = 1764
Subtract 1339.56 from both sides.
b^2 = 425.44
Square root both sides.
b = 20.6 inches

Answer 2

A^2 + b^2 = c^2
The diagonal is the hypotenuse (c).
36.6^2 + b^2 = 42^2
1339.56 + b^2 = 1764
Subtract 1339.56 from both sides. 
b^2 = 425.44
Square root both sides. 
b = 20.6 inches