What is the slant height in a wrecking tangle or square pyramid

The height of the pyramid from the Apex straight down to the middle of the base of the pyramid
The distance across the triangular face
The height from the apex right down to the base of the triangles face where it forms a right angle
The edge of a triangular face

The slant height in a wrecking tangle or square pyramid is the height from the apex straight down to the middle of the base of the pyramid.