Answer:
a) mBA = 124 degrees, this is because the angles are supplementary meaning they are equal to 180 degrees. And one angle has been given which was 56 degrees so we subtract that from the total and get 124 degrees.
b) mCE = 37 degrees, this is because we know the line that is exactly straight in the middle is equal to 180 degrees (supplementary). We are also given the length of the right bottom side which is 56, because it is vertical to the other angle diagonal from it. With two given angles we combine them and subtract it from the total so, 180(total) - (87 + 56)(given angles) = 37
c) I don't know this one, sorry.
