Evidence of base angles theorem

The base angles theorem says that if the sides of a triangle are congruent (isosceles triangle) then the angles opposite those sides are congruent

Start with the following isosceles triangle. The two equal parts are presented with a red mark and contrary to these sides angles are also shown in red


The strategy is to draw the perpendicular bisector of vertex c segment AB

Then use SAS postulate to demonstrate that the trained two triangles are congruent

If the two triangles are congruent, the corresponding angles to be congruent

Draw the perpendicular bisector of c

base-angles-imageSince the angle c is cut in two,

angle (x) = angle (y)

Segment AC = segment BC (it has been given)

FC = FC segment segment (on the side of the commune is the same for the triangle ACF and triangle BCF)

Triangles ACF and triangle BCF are consistent and then by SAS or side angle

In other words, by

AC-angle (x) – FC


BC-angle (y) – FC

Since the limit ACF and BCF triangle are congruent, angle angle = B

Math game: solve a mathematical problem and then eat the math man need a quick response to your basic math problems?
Get an answer in 10 minutes or less by an expert in mathematics!

The capabilities of high calibre math handpicked by staff experts Justanswer after that they have taken and passed a rigorous test of mathematics and their credentials have been verified by a third party

I am also a justanswer expert. If you want to sign me to answer your questions, browse the list of math experts, select my name or request for me (Jetser Carasco) before sending your question

To learn more and ask a math question now

Page copy protected against web site content infringement by Copyscape

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s