Answer:
360°
Step-by-step explanation:
According to the properties of parallel lines, the following deductions can be made:
<a and <c are exterior angles of same side, therefore they are supplementary.
Thus,
m<a + m<c = 180°
<b and <d, are alternate interior angles, therefore, they are supplementary.
Thus, m<b + m<d = 180°.
The total numbers of degrees of a, b, c, d will all sum up to give 360°.
