Classify Triangle

Use the sides to identify the triangle

0 sides the same - scalene triangle

2 sides the same - isosceles triangle

3 sides the same - equilateral triangle

Use the angles to classify the triangles

Use the angles to classify the triangles

all angles less than 90° - acute triangle

1 angle is equal to 90° - right triangle

1 angle is greater than 90° - obtuse triangle

Use the angles to classify the triangles

LOOKING AT ANGLES: WHAT TYPE OF TRIANGLE IS THIS? HINT: ONE ANGLE = 90 DEGREES

• ACUTE

• OBTUSE

• RIGHT

Why is the triangle classified as isosceles?

• All angles are acute

• At least two sides are congruent

• At least one angle is acute

• All angles are congruent

equilateral acute

isosceles right

scalene acute

• equilateral acute

• isosceles right

• scalene acute

Identify all the correct terms to describe the triangle shown.

• Obtuse

• Equilateral

• Isosceles

• Right

• Acute

This is a right triangle because —

• it is facing the right way

• it has 3 acute angles

• it has one 90 degree angle

• it does not have one obtuse angle

Leah drew a triangle on a piece of paper. She made one side 5 inches long, another side 4 inches long, and the final side 3 inches long. What kind of triangle did she create?

• Equilateral

• Scalene

• Straight

• Isosceles