Answer:
A
Explanation:
the length of arc XY is calculated as
arc = circumference of circle × fraction of circle
= 2πr ×
( r is radius and Θ is central angle )
here arc = 40 and r = 10 , then
2π × 10 ×
= 40
20π ×
= 40 ( cancel 20π and 2π by 2π )
10Θ = 40 ( divide both sides by 10 )
Θ = 4 radians