1. GETTING TO KNOW TRIANGLES 7 TH GRADE MATH BY MRS. BRUSH

2.  Triangles are everywhere.  They can be found bracing a bridge.

3.  Triangles can be found racking up billiard balls.

4. Triangles can be seen holding up shelves.

5.  A triangle is a polygon with 3 sides.  Triangles can be classified by sides.  Triangles can be classified by angles.

6. TRIANGLES BY SIDES  SCALENE  ISOSCELES  EQUILATERAL

7. SCALENE TRIANGLE  WHEN 3 PEOPLE GET ON THE SCALES TO SEE HOW MUCH THEY WEIGHT, EACH ONE WEIGHS A DIFFERENT AMOUNT. SO…………

8.  A scalene triangle has no equal sides. All sides are different lengths.

9. Isosceles Triangles  Isosceles triangles have 2 equal sides.  The angles opposite the equal sides are also equal. <B = <C AB = AC

10. Equilateral Triangles  All 3 sides of an equilateral triangle are equal.  Each angle of an equilateral triangle are equal.  Each angle must be 60 degrees.

11.  Now let’s review.  What kind of triangle has all 3 sides and angles equal?

12. Equilateral Triangle

13.  What kind of triangle has all sides a different length ?

14. SCALENE TRIANGLE

15.  What kind of triangle has 2 equal sides?

16. AN ISOSCELES TRIANGLE

17. TRIANGLES BY ANGLES AcuteRightObtuse

18. Acute triangles All angles are less than 90 degrees.

19.  A right triangle has one 90 degree angle.

20. OBTUSE TRIANGLE  An obtuse triangle has one obtuse angle. The obtuse angle is more than 90 but less than 180 degrees.

21. DISCUSSION QUESTIONS  Is it possible to have a right equilateral triangle?  Could you have a triangle that is isosceles and acute?

22. CREDITS  Microsoft clip art.  wwwmath.com/school/subject/practice  www.harcourtschool.com/glossary/math2