Question

(E) ABCD is a rectangle In which AB = 45 m and BC = 42 m and E, F, G and H are the mid point of the sides AB, BC, CD, and DA. Find the cost of lying tiles in the shaded part, if cost of lying tiles is 5 per m². ​

Answer 1

Answer:

  (D)  ₹4725

Step-by-step explanation:

You want the cost of laying tile in half a 45 m by 42 m rectangle if tiles cost ₹5 per square meter.

Area

The area of the shaded part of the rectangle is half the entire area of the rectangle. You know this because the unshaded area is a rhombus with diagonals equal in length to the sides of the rectangle. The area of that rhombus is half the product of its diagonals, hence half the area of the rectangle.

  Shaded area = (1/2)(45 m)(42 m) = 945 m²

Cost

Each square meter costs ₹5 for the tile, so the total cost is ...

  (945 m²)(₹5/m²) = ₹4725 . . . . . matches choice D