기하학 정리 12번째

arbitrary: 

 

exterior angle : 

 

transversal : 

 

used to describe a shape whose sides are all the same length:

 

What we' ve got over here is

a triangle where all three sides

have the same lengths (SSS Congruence)

are congruent each other

 

And a triangle like this

we call equilateral.

we call equilateral.

 

And a trangle like this

we call equilateral

quilateral

quilateral

equilateral

equilateral

equilateral

equilateral

 

 

if two legs

then the base angles

 

We know angle ABC

is congruent to angle ACB.

 

So what we showed in the last

video on isoceles triangles

is that if two base angles are the smae,

 

then the corresponding legs 

are also going to  be the same.

 

So we know, for example,

And we know that the base angle

is congruent