45-45-90 and 30-60-90

45-45-90 and 30-60-90 5-26-09 Sia IMP3

Today’s Agenda • Bell ringer • Hand back HW and quizzes • 45-45-90 triangles • Supplemental Assignment: due Friday, May 29th

Announcements • ACT session this Saturday in room 208 from 8am-10am • EC due next Friday, June 5th • # of students who completed HW4 • 3rd period: 14 out of 23 (61%) • 4th period: 9 out of 17 (53%) • 5th period: 13 out of 17 (76%) • Class average on last week’s quiz • 3rd period: 38/50 = 76% • 4th period: 42/50 = 84% • 5th period: 39/50 = 78%

45-45-90 triangles • As you saw on your bell ringer, if two angles of a triangle are equal, then the sides opposite them are equal in length. • For right triangles, when this happens, it’s called a 45-45-90 triangle.

For ANY 45-45-90 triangle… • For any 45-45-90 triangle, instead of using Pythagorean Theorem, you can determine the lengths of the side by… • BOO-BOO-BOO ROOT 2 BOO√ 2 BOO BOO

Examples: 5 89 5 89

Try these… For a 45-45-90 triangle, find the following: • A leg is 10 feet long • A leg is 34 meters long • The hypotenuse is inches long • The hypotenuse is cm long • The hypotenuse is 6 feet long

45-45-90 and 30-60-90