Don't know about the TV problem, sorry.
For the next one (Dylan) = 14.1 inches
Use the Pythagorean Theorem a^2+b^2 = c^2
10^2 + 10^2 = c^2
100 + 100 = c^2
200 = c^2
Take the square root of both sides. The hypotenuse is equal to the square root of 200, which is 14.1 when rounded to the nearest tenth of an inch.
Hope this helps
