45-45-90 right triangles Some right triangles are used so frequently that it is helpful to remember some of their properties. These triangles are called special right triangles The 2 most common are the 45-45-90 triangle and the 30-60-90 triangle. Since the 45-45-90 triangle has 2 angles with equal measures, it is also an isosceles right triangle
Properties of a 45-45-90 triangle: side lengths In a 45-45-90 right triangle, both legs are congruent and the length of the hypotenuse is the length of the leg multiplied by
Finding side lengths in a 45-45-90 triangle Use the properties to find the length of the hypotenuse of the triangle The length of the hypotenuse is equal to the length of the leg times 45 2 in
Finding side lengths Find the length of a leg of the triangle The length of the hypotenuse is the length of the leg times 3 ft 45
Finding perimeter of a 45-45-90 triangle Find the perimeter 12 + 12 + ? = Perimeter 12 yd. 45
Though it is faster to use the properties of 45-45-90 triangles to find unknown lengths, the Pythagorean theorem can still be used
Applying Pythagorean theorem Find the length of the missing sides using Pythagorean theorem 125 ft 45
review 1. Find the length of the hypotenuse in a 45-45-90 triangle with a leg of 31 yd. 2.Find the length of a leg in a 45-45-90 triangle if the hypotenuse is 63 m. 3. Find the perimeter of a right triangle with an45 degree angle and a leg of 18 in. 4. A square building has a diagonal of 150 feet. What would be the square footage of 1 floor of the building.