ok so we can start off by noticing that the small triangle is similar to the larger triangle, and if triangle's are similar, the angle measures are the same.
so, a = 40 degrees
since the two sides are congruent, that means that angle c is equal to angle a, so angle c = 40 degrees
for angle b, we already know that the other 2 angles of the smaller triangle are both 40, so using the triangle theorem, we get 180-40-40= 100 degrees. so, b = 100 degrees.
lastly, angle e is part of a straight line with the other angle being 40 degrees. so angle e = 180-40=140 degrees
adding them all up becomes 40+40+100+140= 320 degrees