Question

2. A floral design on the floor of a building consists of 2800 tiles. Each tile is in the shape of a parallelogram
of altitude 10 cm and base 14 cm. Find the area of the floor covered by the floral design and the cost of
polishing it at the rate of 75 per m2.​

Answer 1

Arc AB subtend ∠ACB and ∠ADB in the same segment of a circle

∴ ∠ACB = ∠ADB = 40°

In ∆PDB,

∠DPB + ∠PBD + ∠ADB = 180° (Sum of angles of a triangle)

⇒ 120° + ∠PBD + 40° = 180°

⇒ 160° + ∠PBD = 180°

⇒ ∠PBD = 180° – 160° = 20°

⇒ ∠CBD = 20°