Question

What is the format of this proof? Given: ∠ABC is a right angle, ∠DBC is a straight angle Prove: ∠ABD is a right angle two-column proof two-paragraph proof flowchart proof one-paragraph proof

Answer 1

its two column proof

Answer 2

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,

$\angle ABC$ is a right angle and $\angle DBC$ is a straight angle($180^{\circ}$) .    (given)

Therefore, $\angle ABD$  must be right angle. ( because, $\angle ABD=\angle DBC-\angle ABC= 180^{\circ}-90^{\circ}=90^{\circ}$)

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'.