This is an equilateral triangle in which all angles equal 60 degrees and all sides are the same length. The structure supports the ceiling of the building in the stairway.
This triangle is a scalene triangle. None of the angles or sides have the same measure. This triangle is used to support the staircase.
This is an isosceles triangle. The two base angles and the two legs have the same measurement. This triangle is used to support the wall.
This is an isosceles triangle. The two bottom angles measure the same. The two legs also measure the same length. This triangle helps to support the window.