CK-12 Geometry - Second Edition

1.4. Midpoints and Bisectors http://www.ck12.org

Congruence

You could argue that another word forequaliscongruent. However, the two differ slightly.

Congruent:When two geometric figures have the same shape and size.

We label congruence with a∼=sign. Notice the∼above the = sign.AB∼=BAmeans thatABis congruent toBA. If
we know two segments or angles are congruent, then their measures are also equal. If two segments or angles have
the same measure, then, they are also congruent.

TABLE1.1:

Equal Congruent

= ∼=

used withmeasurement used withfigures

mAB=AB= 5 cm AB∼=BA

m^6 ABC= 60 ◦^6 ABC∼=^6 CBA

Midpoints

Midpoint:A point on a line segment that divides it into two congruent segments.

BecauseAB=BC,Bis the midpoint ofAC.