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The volume of the triangular pyramid below is 256 units 3 . Find the value of x.

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Answer:

Explanation:

We can use the formula for the volume of a pyramid, which is:

V = (1/3) * B * h

where V is the volume, B is the area of the base, and h is the height.

In this case, we have a triangular pyramid, so the base is a triangle. Let's call the length of the base x, and the height of the pyramid h. Then, the area of the base is:

B = (1/2) * x * h

Substituting into the formula for the volume, we get:

256 = (1/3) * (1/2) * x * h * h

Simplifying and solving for h, we get:

256 = (1/6) * x * h^2

h^2 = (256 * 6) / x

h = sqrt((256 * 6) / x)

Now, let's use the given information that the three sides of the base have lengths x, 2x, and 3x, to find the area of the base:

B = (1/2) * x * (2x + 3x) / 2

B = (5/4) * x^2

Substituting this and the expression for h into the formula for the volume, we get:

256 = (1/3) * (5/4) * x^2 * sqrt((256 * 6) / x)^2

Simplifying, we get:

256 = (5/4) * x^2 * sqrt(1536 / x)

256 = (5/4) * x^2 * (sqrt(1536) / sqrt(x))

256 = (5/4) * x^2 * (12 / sqrt(x))

256 = 15 * x * sqrt(x)

Squaring both sides, we get:

65536 = 225 * x^3

Dividing both sides by 225, we get:

x^3 = 65536 / 225

Taking the cube root of both sides, we get:

x = (65536 / 225)^(1/3)

x ≈ 6.4

Therefore, the value of x is approximately 6.4 units.

User Martin Eckleben
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