Answer: Two column proof.
Explanation :
A two-column proof is one common way to organize a proof in geometry.Two-column proof always has two columns where one for statements and one for reasons.
Here,
is a right angle and is a straight angle() . (given)
Therefore, must be right angle. ( because, )
Which is the required proof.
Since, In the above proof both statements and reasons both mentioned, therefore, it is the two column proof.
Note: We can also make a table which consist of two columns, in first we can mention 'statements' while in second column we can mention 'reasons'.