Computer screen area is 108
And we know one side is 12 so the other side is 108/12 = 9
The ratio of the computer screen is 12:9 = 4:3
Since the TV is similar, the ratio is also 4:3
Find x when 20:x as 4:3
20*3 = x*4
60/4 = x
x = 15
Area of TV = 20 * 15 = 300 in^2