5. The sides of a right-angled triangle are 12 cm, 16 cm, 20 cm respectively. A new right angle ? is made by joining the midpoints of all the sides. This process continues for infinite then calculate the sum of the areas of all the triangles so made.
6. The perimeter of a rectangle whose length is 6 m more than its breadth is 84 m. What will be the area of the rectangle?
7. The length and the breadth of rectangular field are in the ratio of 8 : 7. If charges of the painting the boundary of rectangle is at Rs. 10 per meter is Rs. 3000. What is the area of rectangular plot?
8. Find the area of the square whose side is equal to the diagonal of a rectangle of length 3 cm and breadth 4 cm.