1. a c b Created by ﺠﻴﻄ for mathlabsky.wordpress.com

2. In a right triangle, the side opposite the right angle is longest side.It is called the hypotenuse, the other side are called the legs of the triangle Hypotenuse Leg Theorem : the square of the length of the hypotenuse is equal to the sum of the square of the lengths of the two legs a b c

3. Exercise : find the length of the unknown side 6 cm 10 cm 2. 20 cm 16 cm 3. 8 cm 12 cm 15 cm 4. 10 cm 5. 7 cm 5 cm 1. Back

4. To find the distance between two points A and B in the coordinate plane we can use the pythagorean theorem X Y 0 A B 3 ● 6 ● ●1●1 ●5●5 5 – 1 = 4 6 – 3 = 3

5. Given points A and B, find the distance between point A and B X Y 0 B A

6. Exercise : find the distance between each pair of point! 1.A(1, 2), B(4, -2) 2.P(-1, 7), Q(2, -3) 3.R(0, -6), S(-3, 4) 4.K(-3, -4), L(6, 2) 5.M(-2, -4), N(-6, -3) Back

7. 1. Isosceles right triangel (45 0 - 45 0 - 90 0 ) 45 0 x x hyp

8. 2p cm 60 0 2. Right triangle has acute angles measuring 30 and 60 (30 0 - 60 0 - 90 0 ) D A B C 60 0 Let : ∆ABC equilateral triangle 2p cm 30 0 p cm B D 60 0 30 0 C 2p cm p cm B D 60 0 30 0 C Hyp Short Leg Long Leg Hypotenuse = 2 x Short Leg Long Leg = Short Leg x

9. 45 0 x 5 ccm y 2. 60 0 5 cm x y 3. 45 0 6 cm x y 4. 30 0 12 cm x y y 5. 30 0 x 1. Exercise : find the value of x and y ! Back