4. Electricity used by farmers during different parts of a
day for irrigation is as follows:
|
Part of a day
|
Morning
|
Afternoon
|
Evening
|
Night
|
|
Percentage of electricity used
|
30
|
40
|
20
|
10
|
|
Part of a day
|
Percentage of electricity used
|
Measure of the central angle
|
|
Morning
|
30
|
(30÷ 100) × 3600 = 1080
|
|
Afternoon
|
40
|
(40÷ 100)× 3600 = 1440
|
|
Evening
|
20
|
(20÷ 100)× 3600 = 720
|
|
Night
|
10
|
(10÷ 100)× 3600 = 360
|
|
Total
|
100
|
3600
|
