To solve the problem in the uploaded image, let's break it down into parts based on the Bengali text.

Question Breakdown:

1. The rectangular field has:

   • Length increased by 2 meters.
   • Breadth increased by 6 meters.
   • The total area becomes 84 square meters.

   Find the perimeter of the field.

2. Every 25 meters of boundary fence costs 20 Taka. Calculate the total cost of fencing the entire boundary.

Solution:

Part 1: Finding Dimensions and Perimeter

1. Let the original length be $l$ meters and breadth be $b$ meters.

2. From the given changes:

   • New length = $l + 2$
   • New breadth = $b + 6$

3. Area of the rectangle: $(l + 2)(b + 6) = 84$ Expanding: $lb + 6l + 2b + 12 = 84 \quad \Rightarrow \quad lb + 6l + 2b = 72 \quad \text{(Equation 1)}$

   Since