The diagonal of a TV is 30 inches long. Assuming that this diagonal forms a pair of \(30-60-90\) right triangles, what are the exact length and width of the TV?

A. 60 inches by \(60 \sqrt{3}\) inches
B. 15 inches by \(15 \sqrt{3}\) inches
C. \(15 \sqrt{2}\) inches by \(15 \sqrt{2}\) inches
D. [tex]\(60 \sqrt{2}\)[/tex] inches by [tex]\(60 \sqrt{2}\)[/tex] inches



Answer :

To determine the length and width of the TV with a given diagonal of 30 inches, we utilize the properties of a [tex]$30-60-90$[/tex] right triangle.

### Step-by-Step Solution:

1. Identify the properties of a [tex]$30-60-90$[/tex] triangle:
In a [tex]$30-60-90$[/tex] triangle, the sides are in a specific ratio:
- The shortest side (opposite the [tex]$30^\circ$[/tex] angle) is of length \( x \).
- The side opposite the [tex]$60^\circ$[/tex] angle (the longer leg) is \( x\sqrt{3} \).
- The hypotenuse (the side opposite the right angle, which in this case is the diagonal of the TV) is \( 2x \).

2. Given the diagonal (hypotenuse) is 30 inches:
We use the fact that the hypotenuse in a [tex]$30-60-90$[/tex] triangle is \( 2x \).

[tex]\[ 2x = 30 \][/tex]

3. Solve for \( x \):
[tex]\[ x = \frac{30}{2} = 15 \][/tex]

4. Determine the lengths of the sides:
- The shorter leg (opposite the [tex]$30^\circ$[/tex] angle) is \( x = 15 \) inches.
- The longer leg (opposite the [tex]$60^\circ$[/tex] angle) is \( x\sqrt{3} = 15\sqrt{3} \) inches.

5. Result:
The lengths corresponding to the sides of the triangle are therefore 15 inches and 15\(\sqrt{3}\) inches respectively.

Combining these steps, the length and width of the TV are 15 inches and \( 15\sqrt{3} \) inches, respectively.

Therefore, the correct answer is:
[tex]\[ \boxed{ \text{B. } 15 \text{ inches by } 15 \sqrt{3} \text{ inches}} \][/tex]

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