Question

The measure of the obtuse angle is the I saucily’s triangle is 2 1/2 times the measure of one base angle right and solve a system of linear equations to find the measures of all the angles

Answer 1

Let o represent the obtuse angle, and let the base angle be represented by b. Then you have
.. o = 2.5b
.. o +2b = 180
Substituting the first equation into the second, you have
.. 2.5b +2b = 180
.. 4.5b = 180
.. b = 180/4.5 = 40
.. o = 2.5*40 = 100

The obtuse angle is 100°; the base angles are 40°.