a square pyramid has 4 triangles
One square and four triangles.
4 right triangles
2 are in a square
A square based pyramid has 4 triangular faces and 1 square face.
two
the answer is pyramid
68
4
Four of them
Triangles are rigid, quadrilaterals are not - a square can be "squashed" into rhombus.
Five. Four triangles and one square make up a square pyramid.