The sum of lengths of all sides of a closed plane figure is called \( \begin{array}{llll}\text { (a) area } & \text { (b) perimeter } & \text { (c) volume } & \text { (d) length }\end{array} \) A string 16 cm long is used to form a square. The length of side the square is \( \begin{array}{llll}\text { (a) } 4 \mathrm{~cm} & \text { (b) } 6 \mathrm{~cm} & \text { (c) } 3 \mathrm{~cm} & \text { (d) } 48 \mathrm{~cm}\end{array} \)

Let's address each question one by one: --- ### **1. The sum of lengths of all sides of a closed plane figure is called** **Options:** - **(a) area** - **(b) perimeter** - **(c) volume** - **(d) length** **Answer:** **(b) perimeter** **Explanation:** - **Perimeter** is defined as the total length around a closed figure, which is the sum of the lengths of all its sides. - **Area** measures the surface covered by the figure. - **Volume** pertains to the space occupied by a three-dimensional object. - **Length** generally refers to the measurement of something from end to end, not necessarily the sum around a shape. --- ### **2. A string 16 cm long is used to form a square. The length of a side of the square is** **Options:** - **(a) 4 cm** - **(b) 6 cm** - **(c) 3 cm** - **(d) 48 cm** **Answer:** **(a) 4 cm** **Explanation:** - For a **square**, all four sides are equal in length. - The **perimeter** of the square is given by the total length of the string, which is 16 cm. \[ \text{Perimeter} = 4 \times \text{Side length} \] \[ 16\, \text{cm} = 4 \times \text{Side length} \] \[ \text{Side length} = \frac{16\, \text{cm}}{4} = 4\, \text{cm} \] - Therefore, each side of the square is **4 cm** long. ---