Q.1 Here you find four nets (Fig 15.10). There are two correct nets among them to make a tetrahedron. See if you can work out which nets will make a tetrahedron.
A tetrahedron is a three-dimensional shape with four triangular faces. It has four vertices and six edges.
A net of a tetrahedron consists of four triangles arranged in such a way that they can be folded to form the tetrahedron.
Out of these four nets, we can make a tetrahedron with net (i) and (iii)
Piramid has only four sides so iv is not ,then if we will see first one then we will get base and its edges and in second one we will not get base but in third one we will get base and edges. So the answer is I and III one