Classifying Triangles

Can the following 3 numbers be side measures of a triangle

10, 18, 10

• Yes

• No

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

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

Classify the triangle by its angle measures ​ (a)   and side lengths ​ (b)  

• right

• Scalene

• obtuse

• acute

• equilateral

• isosceles

• equiangular

Side Classification: ​ (a)  

Angle Classification: ​ (b)  

• Isosceles

• Acute

• Right

• Obtuse

• Equilateral

• Scalene

Classify the following triangle​ .​ ​ ​ ​ ​ ​ ​ ​ ​ ​​ ​ (a)   ​ (b)   ​ (c)   ​

• right triangle

• acute triangle

• obtuse triangle

Classify this triangle.

e

right isosceles

acute equilateral

acute isosceles

right scalene

acute scalene

Side Classification: ​ (a)  

Angle Classification: ​ (b)  

• isosceles

• right

• scalene

• obtuse

• equilateral

• acute

Classify this triangle.

b

acute equilateral

right scalene

right isosceles

acute isosceles

obtuse scalene