Question

The angles of a triangles are x°, 3x° and 30°. When asked to solve for x, Alvi shows the work in post-it A below. Brian shows the work in post-it B below. Who is correct and why? Why mistake did the incorrect person make?

that is the pic for post it a.
the post it b said

x + 3x + 30 = 180
4x + 30 = 180
4x = 150
x = 37.5

Answer 1

See explanation

Explanation:

OK. Alvi is incorrect because he didn't add the measures of all 3 angles of the triangle, whereas Brian did. So, Brian is correct and Alvi needs to work on that kind of problem.