Answer:
The angle ACB is 9 degrees.
Explanation:
To solve this problem we just need to observe the point B, which has two angles and both of them are on a straight angle, this means that the sum of angle ABC and CBD is 180, that is
![\angle ABC + \angle CBD = 180\°](https://img.qammunity.org/2021/formulas/mathematics/high-school/68vae2hd4d9z21p975n7wd1raw8fnxueww.png)
We know that
, then
![\angle ABC+29=180\\\angle ABC=180-29=151](https://img.qammunity.org/2021/formulas/mathematics/high-school/6iax85olhh65wnou06g57tspujycszixw8.png)
Now, in the triangle ABC, we know that all three angles must sum 180
![\angle CAB + \angle ABC + \angle BCA = 180\\20+151+ \angle BCA = 180\\\angle BCA = 180-20-151\\\angle BCA = 9=\angle ACB](https://img.qammunity.org/2021/formulas/mathematics/high-school/dv00eyp7h2kfhd3de763d7g6vul7vq69t4.png)
Therefore, the angle ACB is 9 degrees.