Question

A WINDOW PANE IS IN THE SHAPE REGULAR OCTAGON FIND THE COST OF POLISHING THE WINDOW PANE AT ₹2.50 PER M²​

Answer 1

Answer:

side of regular octagon is not given in the question. Let us assume the side of regular octagon is a m.

As shown in figure octagon can be divided into 8 triangles similar to ΔOBC and the angles are shown in figure.

Area of octagon = 8×(1/2)×a×h = 8×(1/2)×a×(a/2)×tan67.5 ≈ a2 × 4.83 m2

Cost of polishing = a2 × 4.83 × 2.5 = 12.08×a2