Question

find the lateral surface area of this square - based pyramid. lsa = ? ft²

Explanation:

Step1: Find the area of one triangular face

The formula for the area of a triangle is \(A=\frac{1}{2}\times base\times height\). Here, the base \(b = 10\) ft and the height (slant height) \(h=10\) ft. So, \(A_{triangle}=\frac{1}{2}\times10\times10 = 50\) \(ft^{2}\).

Step2: Calculate the lateral surface area

A square - based pyramid has 4 triangular faces. The lateral surface area \(LSA\) is the sum of the areas of these 4 triangular faces. So, \(LSA = 4\times A_{triangle}\). Substituting the value of \(A_{triangle}\) from Step 1, we get \(LSA=4\times50\).

Answer:

\(200\)