# Aflagstaff is placed at one corner of rectangular field of 40m×30m. If angle of elevation of top of flagstaff is 30°.Find height flagstaff?

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- PuzzlingLv 71 month ago
For a faster response, post this in Mathematics next time.

The distance along the diagonal is 50 m. You can show that using the Pythagorean Theorem or just using the fact that a 3-4-5 triangle is a right triangle.

Now draw the triangle formed by the diagonal (50 m) and a flag pole of height x. The angle is 30°.

We can use our knowledge of 30-60-90 triangles and the ratio of their sides:

short : hypotenuse : long = 1 : 2 : √3

In your triangle, the short leg is x and the long leg is 50.

short : long = x / 50

In the ratio:

short : long = 1 / √3

So set up an equation:

x / 50 = 1 / √3

Multiply both sides by 50

x = 50/√3

Rationalize the denominator:

x = (50√3)/3

x ≈ 28.9 m

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