What does it mean to refer to a 20-in TV or 25-in TV set? Such units refer to diagonal of the screen. A 15-in TV set also has the width of 12 in. What is the height?

Question

What does it mean to refer to a 20-in TV or 25-in TV set? Such units refer to diagonal of the screen. A 15-in TV set also has the width  of 12 in. What is the height?

jim_thompson5910 · Answer

a^2+b^2 = c^2  ... the pythagorean theorem


12^2+b^2 = 15^2 ... a = 12 (the width) and c = 15 (the diagonal)


From here, we solve for b


144 + b^2 = 225


b^2 = 225 - 144


b^2 = 81


b = sqrt(81) ... Note: all lengths are positive, so we're dealing with the positive square root


b = 9


So the height is 9 inches