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# definition of solid shapes

Question:hi my son has a test tomorrow and has forgotten his book for revision!!! He is in p5 (9years) old and the test is on pyramids and prisms. He needs to know how many faces vertices and edges each f the following have: pyramid - triangle based, square based, pentagon based and hexagon based prisms - triangular, square, pentagonal and hexagonal can anyone help point me to a website or just tell me the answers. i think i know but am afraid in case i teach him the wrong thing :( Thanks in advance xoxoxoxooxo

Question:

Answers:If it is a solid shape, how do you know that there are only "2 faces?" A sphere has 1 face, A tetrahedron (pyramid with a triangular base) has 4 faces, A cube has 6 faces, Then we have: Octahedrons, Dodecahedrons, Icosahedrons, etc. ad nausium. The only REGULAR 2 faced solids I can think of are hemispheres (or spheroids with some portion of their shape sliced cleanly off) and cones. Depending on the angle of the slice, this leaves us with only circles and ellipses for plane shapes. If it is an IRREGULAR 2 faced solid you will end up with some type of CLOSED CURVE. (Circles and ellipses are also closed curves.) {If you include two infinite cones placed nose-to-nose on the same central line and make a slice (this might not satisfy your definition of a 2 faced solid,) you also have parabolas and hyperbolas.}

Question:

Answers:Its called a tetrahedron. One of the platonic solids. Tetra = 4 sided. Since in 3 dimensional space it is 4 triangles glued together at the edges (think triangle based pyramid) Cheers!