Q50 of 153 Page 148

If the vertical angle of a triangle is 130°, then the angle between the bisectors of the base angles of the triangle is

Let x and y be the bisected angles.


So in the original triangle, sum of angles is


130 + 2x + 2y = 180


2(x + y) = 50


x + y= 25


In the smaller triangle consisting of the original side opposite 130 and the 2 bisectors,


x + y + Base Angle = 180


25 + Base Angle = 180


Base Angle = 155o

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