Is there any theorem or postulate that could prove that CB and EF are congruent? it could be multiple steps but i have no idea. ill give brainliest if its right :)

AAS (angle, angle, side)

Step-by-step explanation:

If two angles and the non-included side of one triangle are equal to the corresponding angles and side of another triangle, the triangles are congruent. The Angle Side Angle Postulate (ASA) says triangles are congruent if any two angles and their included side are equal in the triangles. An included side is the side between two angles. hope this helps you :)

-7/8

step-by-step explanation:

instead of subtracting you add the -6/8 and -1/8