Prove that in any triangle,the outer angle at a vertex is equal to the sum of the inner angles at the other two vertices.
let a triangle be GUN and the the outer angle on the vertex be angle X
now G+U+N = 180
and angle N+X = 180 (linear pair)
now, G+U+N = N + X
now here from both LHS and RHS the angle N will cut off
so, now we were remain of G+U = X ( here G and U is your two interior angle and angle X is your outer angle)
here we proved this
now G+U+N = 180
and angle N+X = 180 (linear pair)
now, G+U+N = N + X
now here from both LHS and RHS the angle N will cut off
so, now we were remain of G+U = X ( here G and U is your two interior angle and angle X is your outer angle)
here we proved this