Pls help... Your friend claims that two isosceles triangles, triangles ABC and DEF are congruent if two corresponding sides are congruent. He explains that there are only two different lengths of sides, so if AB is congruent to DE and BC is congruent to EF, then it must follow that CA is congruent to FD. Explain the error in his reasoning.
(There was no picture to go along with it)

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads