OBJECTIVE I will use the Pythagorean Theorem to find missing sides lengths of a RIGHT triangle.
leg - sides adjacent to right angle leg hypotenuse - longest side - opposite of right angle Right angle - one 90 0 angle The Right Triangle
What is the Pythagorean Theorem? The theorem that the sum of the squares of the lengths of the sides of a right triangle is equal to the square of the length of the hypotenuse. Used to find the missing side of a triangle when two sides are given *Only works with right triangles The formula is: - where a and b are the legs of a triangle and c is the hypotenuse of the triangle
1. Square both legs 3 ft 4 ft 3 ft
2. Count the total squares 3 ft 4 ft 3 ft = 25
3 ft 4 ft 3 ft = Put that number of squares on the hypotenuse
3 ft 4 ft 3 ft = Count the number of squares that touch the hypotenuse # = 5
3 ft 4 ft 3 ft = 25 5.That number is the length of the hypotenuse # = 5 Length = 5
Using the Pythagorean Theorem –Start with the formula –Determine what numbers go with the variables a, b, and c a and b are the legs c is the hypotenuse –Substitute the numbers into the formula and solve
Example - Finding the Hypotenuse a = 6 b = 8 c = ? Equation Substitute Exponents Add Find Square Root Length must be positive
Guided Practice Find the length of the hypotenuse.
Finding a Leg Find the leg of a right triangle with one leg that is 9cm and a hypotenuse of 12cm. Equation Substitute Subtract 81 from both sides Find Square Root Length is Positive The other leg is 12cm.
Guided Practice Find the leg of a right triangle with one leg that is 12cm and a hypotenuse of 20cm.
Independent Practice 1.Find the hypotenuse of a right triangle with legs of 3in and 4in. 2.Find the leg of a right triangle with a leg of 15ft and a hypotenuse of 25 feet.