(a) In the diagram, AB // CD and BC // FE. and . Find the angles marked x and y. (b) The diagram shows a circle ABCD with centre O and radius 7 cm. The reflex angle AOC = 190° and < DAO = 35°. Find : (i) < ABC ; (ii) < ADC. (c) Using the diagram in (b) above, calculate, correct to 3 significant figures, the length of : (i) arc ABC ; (ii) the chord AD. [Take ].
Explanation
(a) 105° + 26° + x = 180° 131° + x = 180° x = 180° - 131° = 49°. 131° + x + 131° + 360 - y = 360° 131° + 49° + 131° + 360 - y = 360° 671° - y = 360° y = 671° - 360° = 311°. (b)(i) = (ii) = = = 85° (c) (i) = = (3 significant figures) (ii) = = (3 significant figures)
