This lesson will concentrate on the 45-45-90 degree triangle and review problems for the 30-60-90 triangle.In a 45-45-90, the 2 legs opposite the 45deg. angles are equal. The hypotenuse is S the square root of 2. A 45-45-90 triangle was presented with one side equal to 3cm. The hypotenuse and leg were determined. A second triangle was given with a hypotenuse of 12cm, the legs had to be determined. A review problem with a 30-60-90 triangle was given with the leg opposite the 30 listed as 4. The hypotenuse and second leg was determined. A square with a diagonal of 15 cm was given and the length of the side of the square determined. The altitude of an equilateral triangle was determined given a side measurement. Finally using the area formula for a triangle, the area of an equilateral triangle with a side of 10 cm was given.