In a [tex]30^{\circ}-60^{\circ}-90^{\circ}[/tex] triangle, the length of the hypotenuse is 30. Find the length of the longer leg.

A. 15
B. [tex]10 \sqrt{3}[/tex]
C. [tex]15 \sqrt{2}[/tex]
D. [tex]15 \sqrt{3}[/tex]

Please select the best answer from the choices provided:
A
B
C
D



Answer :

To solve for the lengths of the sides in a [tex]\(30^\circ-60^\circ-90^\circ\)[/tex] triangle, we can use a well-known property of this type of triangle: the sides are in the ratio [tex]\(1 : \sqrt{3} : 2\)[/tex].

Given:
- Hypotenuse = 30

In a [tex]\(30^\circ-60^\circ-90^\circ\)[/tex] triangle:
- The hypotenuse is twice the length of the shorter leg.
- The longer leg is [tex]\(\sqrt{3}\)[/tex] times the length of the shorter leg.

Step 1: Find the length of the shorter leg.
Since the hypotenuse is twice the length of the shorter leg:
[tex]\[ \text{Shorter leg} = \frac{\text{Hypotenuse}}{2} = \frac{30}{2} = 15 \][/tex]

Step 2: Find the length of the longer leg.
The longer leg is [tex]\(\sqrt{3}\)[/tex] times the length of the shorter leg:
[tex]\[ \text{Longer leg} = \text{Shorter leg} \times \sqrt{3} = 15 \times \sqrt{3} \][/tex]

Simplifying the expression for the longer leg, we get:
[tex]\[ \text{Longer leg} = 15\sqrt{3} \][/tex]

Therefore, the length of the longer leg is [tex]\(15\sqrt{3}\)[/tex], which corresponds to option D.

So, the best answer from the choices provided is:
D. [tex]\(15\sqrt{3}\)[/tex]