Given: ΔABC
Prove: The sum of the interior angle measures of ΔABC is 180°.
What is the missing step in this proof?
![Given ΔABC Prove The sum of the interior angle measures of ΔABC is 180 What is the missing step in this proof class=](https://us-static.z-dn.net/files/d04/894054aa650534014d17855f534bcc5d.png)