The vertex angle of an isosceles triangle measures 20 degrees more than twice the measure of one of its base angles. How many degrees are there in a base angle of this triangle?

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Answer 1 · 2016-11-24T06:57:50

The base angles are #40°#

Let the the size of each base angle be #x#.

The vertex angle is twice #x#, with another #20°#
Vertex angle = #2x+20°#

The sum of the three angles in a triangle is always 180°

#x+x+x^2+20° = 180" "larr # now solve the equation

#4x+20° = 180°#

#4x = 180°-20°#
# #4x = 160°#

#x = 160/4#

#x = 40°#

The angles are #40°, 40° and 100°#