Answer:
35 degrees
Step-by-step explanation:
The angles in a triangle and a straight line add up to 180 degrees.
So adding the angles together:
BCD + BCA = 180
75 + BCA = 180
BCA = 115
Then,
BCA + BAC + ABC = 180
115 + 40 + ABC = 180
Therefore,
ABC = 35 degrees
3x : 2 = 15
3x = 15 * 2
3x = 30
x = 30 : 3
x = 10
--------------------------------
3(10) :2 = 15
