# What Does Corresponding Parts Mean?

In geometry, corresponding parts are parts that relate to each other, such as in congruent triangles.  If two triangles are congruent, their congruent parts are corresponding. When two lines are intersected by a transversal, you also get corresponding parts.  Each vertex has made 4 angles.  The 4 angles on one vertex correspond to the 4 angles on the other vertex.  There are 4 pairs of corresponding angles.  If the lines are parallel, the corresponding angles are congruent.  A picture would be helpful.I always think of it as the parts that match up because they're the "same" but that's not a good technical definition.  I think another type of example could be families.  My family has 4 members: Mom, dad, brother, me.  My parents had friends with the same family structure: Mom, dad, older brother, younger sister.  So the mom's are like corresponding parts, as are the dads, and the brothers, and the sisters.  We were all the same ages too, making us congruent.  But we could be different ages and still be corresponding.
If you had a 3-4-5 and 6-8-10 triangle, the 3 and 6 side correspond.  Even though they are not congruent, they are both the smallest side of their triangle so they match up.
thanked the writer.