## anonymous 5 years ago 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???

1. amistre64

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

2. amistre64

h = 21

3. anonymous

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

4. anonymous

damn i am slow

5. anonymous

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

6. anonymous

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

7. anonymous

so you get $28^2+h^2=35^2$ and then solve for h

8. anonymous

$h^2=35^2-28^2$ etc

9. anonymous

Ok i see what you are saying

10. anonymous

good!

11. anonymous

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

12. anonymous

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

13. anonymous

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

14. anonymous

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