2. © M. Tallman

3. All three sides are congruent. 4 inches 4 inches 4 inches All three angles are also congruent, 60°. 60° 60° 60° Note: an equilateral triangle will always have three 60° angles, no matter what the size of the triangle.

4. Two sides are congruent. 4 inches 3 inches 4 inches Two angles are congruent. 70° 70° 40° One side has a different length. One angle is different. Click here for a helpful trick.

5. © M. Tallman All sides are different lengths. 5 inches 7 inches 3 inches All angles are different. 50° 20° 110°

6. Has one right angle. 90° Note: It is not possible for a triangle to have more than one right angle.

7. All three angles are acute (less than 90°). 50° 60° 70°

8. One angle is obtuse (greater than 90 °). 1 1 0 ° Note: It is not possible for a triangle to have more than one obtuse angle.

9. X° Z° Y° a u n i t s b u n i t s c u n i t s Classify the triangle: Equilateral, Isosceles, Scalene, Right, Acute, Obtuse. Each triangle can be classified in two ways.

10. © M. Tallman 90° X° Y° a u n i t s b units c u n i t s Classify the triangle: Equilateral, Isosceles, Scalene, Right, Acute, Obtuse. Each triangle can be classified in two ways.

11. © M. Tallman X° a u n i t s a units a u n i t s Classify the triangle: Equilateral, Isosceles, Scalene, Right, Acute, Obtuse. Each triangle can be classified in two ways.

12. © M. Tallman X° b u n i t s b u n i t s Y° a units Classify the triangle: Equilateral, Isosceles, Scalene, Right, Acute, Obtuse. Each triangle can be classified in two ways.

13. © M. Tallman X° a units X° b units Classify the triangle: Equilateral, Isosceles, Scalene, Right, Acute, Obtuse. Each triangle can be classified in two ways.

14. © M. Tallman Y° a units b units Z° X° c units Classify the triangle: Equilateral, Isosceles, Scalene, Right, Acute, Obtuse. Each triangle can be classified in two ways.

15. © M. Tallman X° a u n i t s b units Y° a u n i t s X° Classify the triangle: Equilateral, Isosceles, Scalene, Right, Acute, Obtuse. Each triangle can be classified in two ways.

16. © M. Tallman Isosceles Trianglesos Can’t remember what an isosceles triangle is? Try using this little trick! The “sos” in isosceles can stand for same- outcast-same. s a m e s a m e outcast O S S Back to slide show