Lesson 9, Topic 1
In Progress

Angles in a Triangle

Lesson Progress
0% Complete

Triangle

Tri-angle means three angles. 

str e1623279740936

A triangle is the simplest form of polygon with three sides and three interior angles. 

Sum of angles in a triangle is 180º

str23 e1623279977622

\( \scriptsize \angle A \: + \: \angle B \: + \: \angle C = 180^o \)

altern tri e1623246716203

 From the above diagram above 

a = y (alternate angles

b = z (alternate angles

but, a + x + b = 180º (sum of angles on a straight line). 

Since a + b = y + z 

Hence x + y + z = a + x + b = 180º

Therefore, the sum of angles of a triangle = 180º

Responses

Your email address will not be published. Required fields are marked *

back-to-top
error: