Page 76 - NUMINO Challenge_D1
P. 76
Problem solving Key Points
1 Dots are marked in the middle of each face of a The dots marked in
regular tetrahedron. Find the name of the solid the middle of each
figure made by connecting the dots. face are the vertices
of the new solid
figure.
2 Dots are marked in the middle of each face of a The number of faces
regular octahedron. Connect the dots to make a of a solid figure and
new solid figure. Find the sum of the number of the number of
faces and vertices of the dual. vertices of the dual
polyhedron are
equal.
73Geometry
1 Dots are marked in the middle of each face of a The dots marked in
regular tetrahedron. Find the name of the solid the middle of each
figure made by connecting the dots. face are the vertices
of the new solid
figure.
2 Dots are marked in the middle of each face of a The number of faces
regular octahedron. Connect the dots to make a of a solid figure and
new solid figure. Find the sum of the number of the number of
faces and vertices of the dual. vertices of the dual
polyhedron are
equal.
73Geometry
