1. A Given: AC || BD
B
BC bisects AD
E
Prove: AC ≅ BD
C
D
2. Notice these in your list of reasons.
|| lines alt int <s ≅
|| lines corresponding <s ≅
The double arrow means the statement is true both ways.
the statement and its converse are true
it's a Biconditional, so both parts have to be true,
or both parts have to be false.
3. Example 1: Given: ΔAEC ≅ ΔDEB
A
Prove: AC || BD
B
E
C
D
Example 2: (Same Diagram) Given: E is the mdpt of
BC and AD
A
B
Prove: AC || BD
E
C
D
4. You try:
A Given: L is the midpoint of AX
AE ≅ LK
LE ≅ XK
L E
Prove: LE || XK
X K
