Answer:
ACD = 76
Step-by-step explanation:
The sum of the interior angles of a triangle total 180 degrees.
The sum of the two angles making up a straight line also total 180 degrees.
In the triangle, we have A + B + C = 180.
On the straight line, we have C + [tex]C^{1}[/tex] = 180, so C = 180 - [tex]C^{1}[/tex]
We now have A + B + (180 - [tex]C^{1}[/tex]) = 180
A + B - [tex]C^{1}[/tex] = 0
(4x + 15) + 21 - (7x + 6) = 0
3x = 30
x= 10
Therefore ACD = 7x + 6 = 76
