If the width of the screen is 28 inches and the diagonal is 35 (this is the hypotenuse of the right triangle with the length and width as its legs!), then…

28^2 + b^2 = 35^2 …. b = 21.

This is also a special case – the legs and the hypotenuse have the ratio 3:4:5 (a so-called 3-4-5 right triangle). If you notice that the width and diagonal divide by 7 to give you the 4 and the 5, then you can use this rule as a shortcut to the answer (7×3 = 21).

Hope this helps!

What do you have? Two equally sized, shaped and proportioned tight triangles.

If you lknow the length of the hypotenuse, and one of the legs, then you can fiond the value of the other leg as follows.

TV Size = C (hypotenuse of right triangle length.)

Leg of triangle = width of TV (Leg B)

IF A^2 + B^2 = C^2, then

A^2 + 28^2 (784) = 35^2 (1225)

So, A (the other triangle leg) = The square root of C^2-B^2, as that would be A^2 , and the square root of A^2 is A.

1225-784 = 441 so the square root of 441, or 21, is the length of the missing leg of the traingles, which is also the height of the screen on the TV.

So (height)^2 + (28)^2 = (35)^2 given to us by the main man Pythagoras.

From there it is just a simple equation to find your answer.

Good luck! and I hope this helps! 🙂

A² + B² = C²

A is 28″ and C is 35″. Just solve for B.