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Three squares are joined together as shown in figure to create a triangle.

What is the sum of angles ∠A+∠B+∠C ?

 

Note: We are referring to the "exterior angles", not the interior angles of the triangle.

 

 Jun 30, 2020
 #1
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Let the three interior angles of the triangle be A', B', and C'

Then, A  =  360o - 90o - 90o - A'  =  180o - A'.

          B  =  360o - 90o - 90o - B'  =  180o - B'.

          C  =  360o - 90o - 90o - C'  =  180o - C'.

 

A + B + C  =  ( 180o - A' ) + ( 180o - B' ) + ( 180o - C' )  =  540o - A' - B' - C'  =  540o - ( A' + B' + C' )

                  =  540o - 180o  =  360o

 Jun 30, 2020

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