# When we cut a corner of a cube as shown in the figure 12.19, we get the cutout piece as :

(a) square pyramid

(b) trapezium prism

(c) triangular pyramid

(d) a triangle

**Solution:**

We know that

A triangular pyramid is a 3D shape in which all the faces are triangles. It is a pyramid with a triangular base connected by four triangular faces where 3 faces meet at one vertex.

If we cut a corner of a cube, we get the cutout piece as a triangular pyramid.

Therefore, the cutout piece is a triangular pyramid.

**✦ Try This: **List out the properties of a triangular pyramid.

The different properties of a triangular pyramid are:

1. A triangular pyramid has 4 triangular faces, 6 edges, and 4 vertices.

2. 3 edges meet at each of its vertices.

3. A triangular pyramid has no parallel faces.

4. A regular triangular pyramid has equilateral triangles for all its faces. It has 6 planes of symmetry.

5. Triangular pyramids can be regular, irregular, and right-angled.

Therefore, the properties of a triangular pyramid are listed above.

**☛ Also Check: **NCERT Solutions for Class 7 Maths Chapter 10

**NCERT Exemplar Class 7 Maths Chapter 12 Problem 16**

## When we cut a corner of a cube as shown in the figure 12.19, we get the cutout piece as : (a) square pyramid, (b) trapezium prism, (c) triangular pyramid, (d) a triangle

**Summary:**

When we cut a corner of a cube as shown in the figure 12.19, we get the cutout piece as a triangular pyramid.

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