WAEC - Mathematics (1988 - No. 34)
A rope of length 18m is used to form a sector of a circle of radius 3.5m on a school playing field. What is the size of the angle of the sector, correct to the nearest degree?
33o
40o
90o
180o
270o
解释
Circumference = 2πr
2 x 22/7 x 3.5 ≅ 22m
22m = 360o
11m = 360/22 x 11 = 180o
2 x 22/7 x 3.5 ≅ 22m
22m = 360o
11m = 360/22 x 11 = 180o