Answer:
(A) 79º
Step-by-step explanation:
We can set up a simple equation to solve this, by using supplementary angles and the information that the problem has given:
x - 8 + 90 + 4x + 3 = 180
Now, we can solve:
x - 8 + 4x + 3 = 90
x - 5 + 4x = 90
5x = 95
x = 19
Since we found x, we can now substitute it into the equation of angle ECD:
4(19) + 3 = 79 = m<ECD (A)
Hope this helps!!
