This question is about Pythagorean theorem, a square + b square = c square
Where a and b represents either leg of the triangle (width or height), and c represents the hypotenuse (the diagonal)
Let height = h
For the question above, the equation will be
36 square + h square = 45 square
Subtract 36 square from both sides
36 square - 36 square + h square= 45 square - 36 square
h square = 2025 - 1296
h square = 729
Find the square root of both sides
Square root of h square = square root of 729
h = 27
The height of the television is 27