The sum of the internal angles of a triangle must be equal to 180 degrees. We were given two of the angles and need to calculate the last one, to do that we will solve the following equation:
[tex]\measuredangle A+\measuredangle B+\measuredangle C=180[/tex]Applying the data from the triangle we have:
[tex]\begin{gathered} \measuredangle A+100+47=180 \\ \measuredangle A+147=180 \\ \measuredangle A=180-147 \\ \measuredangle A=33 \end{gathered}[/tex]The angle A measures 33 degrees.
