The corner of B is equal in a triangle of ABC to 40 degrees and A corner 20 degrees less corner of C find a-degree measure of a corner of A

Let the corner with be equal x °, then and x-20, in raven40 ° (on a condition), knowing that the sum of any treygolnik equally 180 °, we will make the equation 40+ x + x-20=180 20+2kh =180 of the 2nd =180-20 of the 2nd =160 X =160:2 X =80 - a corner with 80-20=60 - a corner And Answer: And =60
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