Question 39

A and C are nets for the regular triangular pyramid.

Both nets A and C effectively represent the triangular pyramid by displaying a triangular base with three triangular faces that can be folded up to form the pyramid structure.

A) ultq120opa-adms.png

This option is correct as it shows a net that includes a triangular base and three adjacent triangular faces. When folded, this configuration will form a regular triangular pyramid, confirming that it is a valid representation of the solid.

B) ultq120opb-adms.png

Option B is incorrect because it does not conform to the requirements of a triangular pyramid net. The arrangement of shapes and their connections does not allow for a proper folding into a pyramid, as it lacks the necessary triangular faces that connect to the base.

C) ultq120opc-adms.png

This option is also correct as it illustrates a net that features a triangular base along with the three triangular faces necessary to create a triangular pyramid. The arrangement allows for a successful folding into the three-dimensional shape, validating it as a correct net.

D) ultq120opd-adms.png

Option D is incorrect because it fails to present a net that can be folded into a triangular pyramid. It either lacks the required triangular faces or has an arrangement that does not support forming the pyramid structure.

Conclusion

Both options A and C meet the criteria for nets of a regular triangular pyramid, showcasing the correct integration of a triangular base and the necessary triangular faces. In contrast, options B and D do not provide the correct configurations needed to form the solid, thereby confirming their incorrectness.