Answer:
1. The tetrahedron has 4 vertices, 6 edges and 4 faces. Then V-E+F=4-6+4=2
2. The cube has 8 vertices, 12 edges and 6 faces. Then V-E+F=8-12+6=2
3. The octahedron has 6 vertices, 12 edges and 8 faces. Then V-E+F=6-12+8=2
4. The icosahedron has 12 vertices, 30 edges and 20 faces. Then V-E+F=12-30+20=2
5. The dodecahedron has 20 vertices, 30 edges and 12 faces. Then V-E+F=20-30+12=2.
1. 17
2. 1
17 and 1
Hope i helped
Well the only thing that would make these triangles not congruent is dilation, Thus, translation, reflection, and rotations all make the triangles congruent.
The bottom one and third one are not congruent while everything else is.
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