Mutual position of lines and interior angles in a triangle

At the end of this activity, students should be able to:
– draw perpendicular lines using a set square
– find the shortest path from a point to a line
– draw parallel lines using a set square
– draw parallel lines using a ruler and a set square
– understand the notions of angles around a point and angles on a line- know about vertical angles
– know the sum of angles in a triangle and apply this property in simple problems.