Please tell me how to do this, I'll mark brainliest if you do

The bottom line is a straight line that is equal to 180 degrees.

The three angles above it all need to add together to equal 180.

One angle is given as 20, so the other two need to add together to equal 160 ( 180-20 = 160)

Those two angles form the angle ACE so the answer would be 160 degrees,

Answer 160 degrees.

i hope this is what you were looking for.

see attached graph