We know the following

\(\displaystyle∠{1}=∠{5}\)

Therefore

\(\displaystyle{2}∠{1}={100}\)

\(\displaystyle∠{1}={1002}={50}\)

We also know that

\(\displaystyle∠{2}={180}−∠{1}\)

\(\displaystyle∠{2}={180}−{50}\)

\(\displaystyle∠{2}={130}\)

\(\displaystyle∠{1}=∠{5}\)

Therefore

\(\displaystyle{2}∠{1}={100}\)

\(\displaystyle∠{1}={1002}={50}\)

We also know that

\(\displaystyle∠{2}={180}−∠{1}\)

\(\displaystyle∠{2}={180}−{50}\)

\(\displaystyle∠{2}={130}\)