How do I find the area of a sector if I know the diameter and the arc length?

It should be included in the problem. If it is a right triangle, use the Pythagorean Theorem (A squared + B squared = C squared) to find the missing side.

Double the radius, then multiply by pi. That gives you the circumference. Divide the length of the arc by the length of the circumference. That gives you the fraction of...

As shown above, the formula is (60°/360°) π (3)² = (1/6)(3.14159)(9). The area will be expressed in square feet.

For the perimeter, add the four sides together and simplify. For the area, multiply the length by the width.

To find the arc length, set up the formula Arc length = 2 x pi x radius x (arc's central angle/360), where the arc's central angle is measured in degrees.

If you're not given the central angle, you'll typically be given the sector area of the arc. To find the arc length with a sector area, multiply the sector area...

Divide the area by the length, giving you the width. Add twice the width to twice the length.

You also need to know the volume, in which case, you would divide the volume by the area.

Let B equal the breadth. Then 2B equals the length. Write an equation in B, stating that the perimeter is equal to twice the breadth plus twice the length. Solve...

This sounds like a good area for constructing a rain garden. Since water pools there, and it is already compacted, it will be easier to work with the natural setting...