Identifying perpendicular lines in shapes. Example geometry questions a Key Stage 2 child might come across are:. Tick the two shapes that have perpendicular lines: In this case, they would need to tick the second and fourth shapes, as these have perpendicular lines (lines at right angles to each other).
And, any 2 vertical lines are parallel. Slopes of Perpendicular Lines. In a coordinate plane, 2 nonvertical lines are perpendicular iff the products of their slopes is -1. Or, Slopes are negative reciprocals. And, horizontal lines are perpendicular to vertical lines. m 1 = 2; m 2 = 2m 1 = 2; m 2 = -½