Given the volume of a pyramid V = (1)/(3)xyh, we need to find the expression for x in terms of V, y, and h.

Here are the solutions to your questions.

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Given the volume of a pyramid $V = \frac{1}{3}xyh$, we need to find the expression for $x$ in terms of $V, y,$ and $h$.

Step 1: Write the given formula.

$$V = \frac{1}{3}xyh$$

Step 2: Multiply both sides by 3 to eliminate the fraction.

$$3V = xyh$$

Step 3: Divide both sides by $yh$ to isolate $x$.

$$x = \frac{3V}{yh}$$

The expression for $x$ is $\boxed{\frac{3V}{yh}}$.

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A right cone with base diameter 18 cm and perpendicular height 8 cm is made to form a sector of a circle.

Step 1: Determine the base radius of the cone.
The base diameter is 18 cm, so the base radius $r$ is half of the diameter.

$$r = \frac{18}{2} = 9 \text{ cm}$$

The perpendicular height $h$ is 8 cm.