Question

2. Find the areas of rectangles with the following pairs of monomials as their lengths and
breadths respectively.
(p, q); (10m, 5n); (20x2, 5y2); (4x, 3x?); (3mn, 4np)​

Answer 1

Arc AB, subtends ∠AOB at the centre and ∠APB at the remaining part of the circle

∴∠AOB = 2∠APB = 2 x 50° = 100°

Join AB

∆AOB is an isosceles triangle in which

OA = OB

∴ ∠OAB = ∠OBA But ∠AOB = 100°

∴∠OAB + ∠OBA = 180° – 100° = 80°

⇒ 2∠OAB = 80°

80°

∴∠OAB = 80∘2  = 40°