Question

Television sets. 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 35-in tv set also has a width of 28 inches. What is the height of a 35-inch tv ...inches???

Answer 1

h = sqrt(35^2 - 28^2)

Answer 2

h = 21

Answer 3

\[h=\sqrt{35^2-28^2}\]
\[h=\sqrt{1225-784}\]
\[h=\sqrt{441}\]
\[h=21\]

Answer 4

damn i am slow

Answer 5

at any rate i hope it is clear that this all comes from
\[a^2+b^2=c^2\] where a and b are the sides and c is the hypotenuse. so you are thinking of the diagonal as the hypotenuse and the sides as 35 and 28

Answer 6

actually i meant you are thinking of the hypotenuse as 35 and one of the sides at 28

Answer 7

so you get \[28^2+h^2=35^2\] and then solve for h

Answer 8

\[h^2=35^2-28^2\] etc

Answer 9

Ok i see what you are saying

Answer 10

good!

Answer 11

if one leg of a triangle is 5 and the hypotenuse is 13 then you know
\[5^2+b^2=13^2\]

Answer 12

solving for b gives first
\[b^2=13^2-5^2\] and then \[b=\sqrt{13^2-5^2}\]

Answer 13

but if you do this often you just go right to the last step

Answer 14

\[h=28 \text{Tan}\left[\text{ArcCos}\left[\frac{28}{35}\right]\right] \]