Parallel lines and the angles they form

We assume that, since the lines are parallel, Corresponding Angles are congruent - for example  $\angle5\cong\angle1$  .  Check any box with Corresponding Angles.

•  $\angle1\ and\ \angle2$  
  

•  $\angle2\ and\ \angle6$  
  

•  $\angle4\ and\ \angle8$  
  

•  $\angle3\ and\ \angle7$  
  

Tags

CCSS.8.G.A.5

So, if  $\angle5\cong\angle1$ , and  $\angle4\cong\angle1$  , what can we conclude?

•  $\angle5\cong\angle4$  These are called Alternate Interior Angles.  They are congruent if they are formed by parallel lines!

• Sweet!

• Cool.

• Right on.

Tags

CCSS.8.G.A.5

Which pair of angles is an example of corresponding angles?

•  $\angle1\ and\ \angle8$  

•  $\angle3\ and\ \angle7$  

•  $\angle4\ and\ \angle5$  

•  $\angle2\ and\ \angle5$  

Tags

CCSS.8.G.A.5

Find $m\angle1.$  

•  $180\degree$  
  

•  $65\degree$  
  

•  $115\degree$  

Tags

CCSS.8.G.A.5

Find $m\angle2.$  

•  $65\degree$  

•  $180\degree$  

•  $115\degree$  

Tags

CCSS.8.G.A.5

What do you know about $\angle1$  and  $\angle2$ ?

• They are congruent.

• They are supplementary.
  

Tags

CCSS.8.G.A.5

Find  $m\angle1.$  

•  $131\degree$  

•  $180\degree$  

•  $49\degree$  

Tags

CCSS.8.G.A.5

What do you know about $\angle1$ and $\angle2$ ?

• They are congruent.

• They are supplementary.
  

Tags

CCSS.8.G.A.5

Which is the correct equation to solve for x?

• $2x-10=4x+16$
  

• $2x-10+4x+16=180$
  

Tags

CCSS.8.G.A.5

Calculate the missing angle.

• 110º

• 80º

• 70º

• 60º

Tags

CCSS.8.G.A.5