Question

How should the two solids be joined in order to form a tetrahedron? 

• A. ci, ag, be
• B. af, bg, ci
• C. ae, ci, bf
• D. ci, ae, dh

Hint:

For solid-joining puzzles, first identify triangular faces that can overlap. Matching vertex-to-vertex gives the correct joining.

Answer 1

The Correct Option is C

Step 1: Recall tetrahedron property.
A tetrahedron has 4 vertices and 4 triangular faces. To form it, we must join two triangular solids so that one triangular face from each overlaps perfectly.
Step 2: Look at Fig 1.
Fig 1 shows vertices \(a, c, d\) forming a triangular face. The edges \(ac, cd, da\) are visible.
Step 3: Look at Fig 2.
Fig 2 shows vertices \(e, f, i\) forming a triangular face. The edges \(ef, fi, ie\) are visible.
Step 4: Match pairs.
To join, we must pair three vertices from Fig 1 with three from Fig 2:
- \(a \leftrightarrow e\)
- \(c \leftrightarrow i\)
- \(b \leftrightarrow f\)
This corresponds exactly to option (C): ae, ci, bf.
Step 5: Conclude.
Thus, the correct connections to form a tetrahedron are given in option (C). Final Answer: \[ \boxed{\text{C – ae, ci, bf}} \]