Lines a, b,c, and d are in the same plane. line a is parallel to line c. lines b and c are perpendicular to line d. based on this, tell how lines a and b are related. justify your answer.

Given that lines a, b, c, and d are in the same plane. Line a is parallel to line c. Line b and c are perpendicular to line d. Therefore, we can say that lines a and b are parallel to each other. Both line a and b are perpendicular to line d.

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.