Algebra
posted by Kimmie .
What does it mean to refer to a 20 in tv set or a 25 in set?Such units refer to the diagonal of the screen. A 35 in unit also has a width of 28 in. What is it's height?

Time for the Pythagorean theorem, since we're dealing with a right triangle here.
a^2 + b^2 = c^2
a^2 + 28^2 = 35^2
a^2 + 784 = 1225
a^2 = 1225  784
a^2 = 441
a = 21 
Thank you Ms. Sue, I can now understand what it was I was looking for. I kept thinking square and not seeing I was actually measuring a right triangle. Thanks again!

You're welcome, Kimmie.