s₁: The length of one side of the triangular base of the pyramid

s₂: The length of a second side of the triangular base of the pyramid

s₃: The length of the third side of the triangular base of the pyramid

H: The height of the triangular base of the pyramid (associated with s₁ in this example)

h₁: The height of the triangular lateral surface associated with s₁ of the triangular base of the pyramid

h₂: The height of the triangular lateral surface associated with s₂ of the triangular base of the pyramid

h₃: The height of the triangular lateral surface associated with s₃ of the triangular base of the pyramid

S: The surface area of the pyramid

To determine the formula for the surface area of any pyramid, find the sum of the areas of every face.