An octahedron.
This would be a triangular prism.
The cone IS a 3d figure.
A triangular prism.
A net has two equilateral triangles and 3 rectangles. What solid figure might it make?
A pyramid.
A triangular pyramid. It has triangles on its 3 sides and a triangle on the bottom for a base.
a pyramid
An octahedron.
A triangular base pyramid would fit the description.
Maltese or Iron Cross!
how many triangles are in a eight sided figure
There can be no closed 3D shape with only one square and 3 triangles.
The simplest pattern is 2n+1, so the 16th figure will have 33 triangles. Of course, if you are creating new triangles and also keeping the old triangles, this would be different.
A hexahedron. A parallelepiped, cuboid, quadrilateral frustum are examples.
origamiresoucecenter.com
A tetrahedron has four equilateral triangles as sides