# RS Aggarwal Class 8 Math Nineteenth Chapter Three-Dimensional Figures Exercise 19A Solution

## EXERCISE 19A

**(1) Write down the number of faces of each of the following figures:**

(i) Cuboid = 6 faces

(ii) Cube = 6 faces

(iii) Triangular prism = 5 faces (2 triangular and 3 rectangular)

(iv) Square pyramid = 5 faces (1 sq. faces and 4 triangular faces)

(v) Tetrahedron = 4 triangular faces

**(2) Write down the number of edges of each of the following figures:**

(i) Tetrahedron = 6 edges

(ii) Rectangular pyramid = 8 edges

(iii) Cube = 12 edges

(iv) Triangular prism = 9 edges

**(3) Write down the number of vertices of each of the following figures:**

(i) Cuboid = 8 vertices

(ii) Square pyramid = 5 vertices

(iii) Tetrahedron = 4 vertices

(iv) Triangular prism = 6 vertices

**(4) Fill in the blanks:**

(i) A cube has ** 8** vertices,

**edges and**

__12__**.**

__6__(ii) The point at which three faces of a figure meet is known as its ** vertex**.

(iii) A cuboid is also known as a rectangular ** cube**.

(iv) A triangular pyramid is called a ** tetrahedron**.