Answer:
20degrees
Explanation:
The sum of angle C and D is 180 degrees since they are supplementary
Given
m<C = 140 degrees
m<D = 2x
Taking the sum and equating to 180
140 + 2x = 180
2x = 180-140
2x = 40
x = 40/2
x = 20 degrees
Hence the value of x is 20degrees