Question

A certain television is advertised as a 41-inch TV (the diagonal length). If the width of the TV is 40 inches, how many inches tall is the TV?

Answer 1

9 inches tall

Explanation:

Use the Pythagorean theorem: you know the hypotenuse (41) and the leg (40)

`a^(2) +40^(2) =41^(2)`

Solve for a:

Simplify exponents

`a^2+1600=1681`

Subtract 1600 from both sides

`a^2+1600-1600=1681-1600\\a^2=81`

Find the square root

`√(a^2)=√(81\\) \\a=9`

Answer 2

9 inches

Explanation:

A^2+b^2=c^2 so

40^2+b^2=41^2

1600+b^2=1681

so b^2=81

so b=9