in the formula for lateral surface area for a square base pyramid is 1/2Pl but what does the little l mean?

The Lateral area of a regular pyramid equals half the perimeter of the base times the slant height (L.A.=1/2pl)

*so the little l is the slant hight

The slanted height of the pyramid or prism?

In the formula for the lateral surface area of a square base pyramid, the symbol "l" represents the slant height of the pyramid. The slant height is the distance from the vertex to the midpoint of one of the sides of the base. It can be calculated using the Pythagorean theorem, where "l" is the hypotenuse, and the base side length and height of the pyramid are the other two sides of the right triangle.

In the formula for the lateral surface area of a square base pyramid, the little "l" typically represents the slant height of the pyramid. The slant height is the distance from the apex (top) of the pyramid to any point on the perimeter of the base.

To find the slant height, you can use the Pythagorean theorem, which states that the square of the hypotenuse (c) is equal to the sum of the squares of the other two sides (a and b) of a right triangle. In the case of a square base pyramid, we can consider one of the triangular faces as a right triangle.

Here's how you can find the slant height (l):
1. Start by finding the length of the diagonal of the base (d). Since the base of a square is formed by equal sides, you can use the formula d = s√2, where s is the length of any side of the base.
2. Divide the diagonal length by √2 to get the length of one side of the triangle formed by the diagonal and the slant height (diagonal ÷ √2).
3. Finally, use the Pythagorean theorem to solve for the slant height (l). The formula is l = √(h^2 + (diagonal/√2)^2), where h is the height (vertical distance from the base to the apex) of the pyramid.

Once you have the slant height (l), you can substitute it into the formula for the lateral surface area of the pyramid: 1/2Pl, where P represents the perimeter of the base.