2/3/21 Geo

2/3 Geo Classifying Triangles

Take notes on the slides and videos. You will be uploading your notes for credit.

Classifying Triangles by angle measure

• Acute Triangle: 3 acute angles

• Equiangular Triangle: 3 congruent acute angles

• Right Triangle: 1 right angle

• Obtuse Triangle: 1 obtuse angle

Classifying Triangles by side length

• Isosceles Triangle: At least 2 congruent sides

• Equilateral Triangle: 3 congruent sides

• Scalene Triangle: No congruent sides

Use the definitions from slides 3 and 4 to match the names to the triangle pictures. Note: Some triangles can be classified in more than one way.

• A: Acute Triangle

• B: Equiangular Triangle

• C: Right Triangle

• D: Obtuse Triangle

• E: Isosceles Triangle

• F: Equilateral Triangle

• G: Scalene Triangle

Fill in the Blanks

Classify the triangle shown by its sides.

Fill in the Blanks

Classify the triangle shown by its angles

Fill in the Blanks

Classify the triangle shown by its sides.

Fill in the Blanks

Classify the triangle shown by its angles

Fill in the Blanks

Classify the triangle shown by its sides.

Fill in the Blanks

Classify the triangle shown by its sides.

Fill in the Blanks

Classify the triangle shown by its angles

Fill in the Blanks

Classify the triangle shown by its sides.

Fill in the Blanks

Classify the triangle shown by its angles

Fill in the Blanks

Classify the triangle shown by its sides.

Fill in the Blanks

Classify the triangle shown by its angles

Fill in the Blanks

Classify the triangle shown by its angles

Fill in the Blanks

Classify the triangle shown by its sides.

Fill in the Blanks

Classify the triangle shown by its angles

Triangle Sum Theorem: The sum of the angles of any triangle will always be 180^o. 

Name and classify the 3 triangles to the right. Justify your answers.

Fill in the Blanks

Find x

Fill in the Blanks

Find DE

Fill in the Blanks

Find DF

Fill in the Blanks

Find EF

Fill in the Blanks

Find X

Fill in the Blanks

Find AC

Fill in the Blanks

Find AB

Fill in the Blanks

Find BC

Answers for the problems in the notes

• 1: C, E / 2: A, E / 3: B, F

• 4: B, F / 5: D, G / 6: D, E / 7: C, G

•  $\Delta EFH\ obtuse\ scalene$  

•  $\Delta EHG\ right\ scalene$  

•  $\Delta HFG\ equiangular,\ equilateral,\ and\ technically\ acute$