Johnson Solid (J1)
If the sides are all equilateral triangles, the pyramid is one of the Johnson solids (J1). The 92 Johnson solids were named and described by Norman Johnson in 1966.
The Johnson square pyramid can be characterized by a single edge-length parameter a. The height H (from the midpoint of the square to the apex), the surface area A (including all five faces), and the volume V of such a pyramid are:
Read more about this topic: Square Pyramid
Famous quotes containing the words johnson and/or solid:
“And God stepped out on space,
And He looked around and said,
“I’m lonely—
I’ll make me a world.””
—James Weldon Johnson (1871–1938)
“The imaginations which people have of one another are the solid facts of society.”
—Charles Horton Cooley (1864–1929)