Question

A4
6 cm
oly
a.
b.
Construct A ABC, where AC = 3.5 cm, BC = 4cm and ZABC = 45°.
Construct A PQR, where PQ = 2.5 cm, ZPQR = 100°, QR = 6 cm.
Construct A ABC, where BC = 7 cm, ZACB = 120°, AC = 5 cm.
Construct AEFG, where ZEFG = 90°, EF = 4 cm, FG = 6 cm.
C.
d.​

Answer 1

In circle with centre O,

∠AOC = 120°, AB is produced to D

∵ ∠AOC = 120°

and ∠AOC + convex ∠AOC = 360°

⇒ 120° + convex ∠AOC = 360°

∴ Convex ∠AOC = 360° – 120° = 240°

∴ Arc APC Subtends ∠AOC at the centre and ∠ABC at the remaining part of the circle

∴ ∠ABC = 12∠AOC = 12x 240° = 120°

But ∠ABC + ∠CBD = 180° (Linear pair)

⇒ 120° + x = 180°

⇒ x = 180° – 120° = 60°

∴ x = 60°