Question

A certain television is advertised as a 13-inch TV (the diagonal length). If the width of the TV is 12 inches, how many inches tall is the TV?

Answer 1

The TV is 5 inches tall

Explanation:

Let us revise the Pythagoras Theorem

In any right triangle

• The legs of the triangle are the two sides of the right angle
• The hypotenuse of the triangle is the side opposite to the right angle
• The relation between the sides of the triangle is square the hypotenuse is equal to the sum of the squares of the two legs of the triangle

The tall and the width of the TV and its diagonal formed a right triangle whose legs are the tall and the width of the TV and the hypotenuse is the diagonal of the TV

∵ Width of TV = 12 inches

∵ Diagonal of TV = 13 inches

- By using Pythagoras Theorem

∵ (Diagonal)² = (width)² + (tall)²

∴ (13)² = (12)² + (tall)²

∴ 169 = 144 + (tall)²

- Subtract 144 from both sides

∴ 25 = (tall)²

- Take √ for both sides

∴ 5 = tall

∴ The TV is 5 inches tall