Max Maths, Year 5, Learn together, Perpendicular lines (1)

In a Year 5 mathematics lesson, students explore the concept of perpendicular lines. The session begins with a practical activity where Jade draws two lines and then uses a protractor to measure the angle where they intersect. This hands-on approach helps students to visually grasp that when two lines meet to form a right angle, they are known as perpendicular lines. The significance of the right angle is emphasized by its precise measurement of 90 degrees, which is a key characteristic of perpendicularity.

The lesson further clarifies this geometric concept by using examples and notation. When referring to the lines in the diagram, the purple line and the red line intersect at an angle of 90 degrees, thus they are perpendicular to each other. The notation AB perpendicular to CD, written as AB ⊥ CD, is introduced, which signifies that line segment AB is perpendicular to line segment CD, and vice versa for CD ⊥ AB. This notation is a shorthand way for students to express and recognize the relationship between two lines that meet at a right angle, reinforcing their understanding of the fundamental properties of perpendicular lines.