Question 271667
What does it mean to refer to a 20-in TV set or a 25-in TV set? 
Such units refer to the diagonal of the screen. 
A 10-in TV set also has a width of 8 inches. 
Question:
What is the height? 
Draw a rectangle that has a width = 8" and a diagonal = 10"
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Let the height be "x".
Use Pythagoras to find "x":
Equation:
10^2 = x^2 + 8^2
100 = x^2 + 64
x^2 = 36
x = 6"
Ans: height = 6"
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Cheers,
Stan H.