Help me solve the problem! Please help

m+n=140

Step-by-step explanation:

So the angles in a triangle always add up to 180. We already know that the first angle in the triangle is 40 degrees because it's shown in the angle below the triangle. So we have 140 degrees left since 40 is taken up. That eans m+n=140

been looking for the answer havent been able to find it   but good luck with it