Answer:
Alternate angles form a 'Z' shape and are sometimes called 'Z angles'. ... d and f are interior angles. These add up to 180 degrees (e and c are also interior). Any two angles that add up to 180 degrees are known as supplementary angles.
If the transversal cuts across parallel lines (the usual case) then exterior angles are supplementary (add to 180°). So in the figure above, as you move points A or B, the two angles shown always add to 180°.
Corresponding angles are equal. ... Adjacent angles add up to 180 degrees. (d and c, c and a, d and b, f and e, e and g, h and g, h and f are also adjacent). d and f are interior angles.
We also know that consecutive angles are supplementary, and 90 + 90 = 180. Therefore, all four angles would have a measurement of 90-degrees.