The conversation between human and AI assistant.
[|Human|] Determine the type of angle created by stright lines AB and CD
[|AI|] The type of angle created by straight lines AB and CD is a right angle, also known as a 90-degree angle. This is because a vertical line and a horizontal line intersect at a right angle.
[|Human|] 
Determine the type of angle created by stright lines AB and CD