Answer:
27.2
Explanation:
Pythagorean theorem states that the sum of the squares on the legs of a right triangle is equal to the square on the hypotenuse.
Since the triangle formed by the diagonal and the base of the TV is a right triangle, then
c^2 = a^2 + b^2 with c is the diagonal (hypotenuse) and a is the base and b is the height
42^2 = 32^2 + b^2
1764 = 1024 + b^2
b^2 = 740
b = √740 = 27.2