Chapter 16 Lesson 4 Triangles

Quick Review Write if each angle is a right angle, acute angle, or obtuse angle

Quick Review Write if each angle is a right angle, acute angle, or obtuse angle Acute angle obtuse angle right angle

Georgia Performance Standard M3G1: Students will further develop their understanding of geometric figures by drawing them. They will also state and explain their properties. a. Students will draw and classify previously learned fundamental geometric figures and scalene, isosceles, and equilateral triangles. c: Students will examine and compare angles of fundamental geometric figures.

Essential Questions How do you describe, identify, and classify geometric figures and scalene, isosceles, and equilateral triangles? How do you classify angles and triangles as right, acute, or obtuse?

You can name triangles by their equal sides. equilateral triangle 2 cm Has 3 equal sides.

isosceles triangle 3 cm 2 cm Has 2 equal sides.

scalene triangle 2 cm 3 cm 4 cm Has 0 equal sides.

You can also name triangles by their angles. right triangle Angle looks like a corner or the letter L turned anyway.

obtuse triangle Has an angle that is larger than a right angle. one obtuse angle

acute triangle Angles are less than a right angle. 3 acute angles

Name the triangle. a.Isosceles b.Equilateral c.Scalene 2 cm

Name the triangle. a.Isosceles b.Equilateral c.Scalene 2 cm It has 3 equal sides.

Name the triangle. a.Isosceles b.Equilateral c.Scalene 4 cm 6 cm 8 cm

Name the triangle. a.Isosceles b.Equilateral c.Scalene 4 cm 6 cm 8 cm It has 0 equal sides.

Name the triangle. a.Isosceles b.Equilateral c.Scalene 4 cm 8 cm

Name the triangle. a.Isosceles b.Equilateral c.Scalene 4 cm 8 cm It has 2 equal sides.

Name the triangle. a.Right b.Obtuse c.Acute 4 cm 8 cm

Name the triangle. a.Right b.Obtuse c.Acute 4 cm 8 cm All angles are less than a right angle.

Name the triangle. Right Obtuse Acute

Name the triangle. Right Obtuse Acute It has an angle like a corner or the letter L.

Name the triangle. Right Obtuse Acute

Name the triangle. Right Obtuse Acute The angle is larger than a right angle.

Lets review the triangles.

equilateral triangle 2 cm Has 3 equal sides.

isosceles triangle 3 cm 2 cm Has 2 equal sides.

scalene triangle 2 cm 3 cm 4 cm Has 0 equal sides.

right triangle Angle looks like a corner or the letter L turned anyway.

obtuse triangle Has an angle that is larger than a right angle. one obtuse angle

acute triangle Angles are less than a right angle. 3 acute angles