Geometry: An Interactive Journey to Mastery



Example 2
*LYHQ ELVHFWV 
.

BD EBC

xz

‘

‘#‘

Prove: AE BD||.
ͼ௘6HHFigure 8.2௘ͽ
Solution
i. ‘#‘yzEHFDXVHBDELVHFWV‘EBC.
ii. ‘#‘xyEHFDXVHZHKDYH‘#‘xzͼ௘JLYHQ௘ͽDQG‘#‘yz.
iii. AE BD|| EHFDXVHZHKDYHFRQJUXHQWDOWHUQDWHLQWHULRUDQJOHV
Study Tip
x 5HDGRXWORXGDQ\SURRI\RXZULWH7KDWZD\\RXZLOOEHDEOHWRDVVHVVWZRWKLQJV
ż 'RHVZKDW\RXZULWH³ÀRZ ́ZHOO"
ż 'RHVZKDW\RXSXWGRZQRQSDSHUDFWXDOO\VD\ZKDW\RXKDYHLQ \RXUPLQG"
Pitfall
x ,QOHDUQLQJWRZULWHSURRIVVWXGHQWVRIWHQPDNHVWDWHPHQWVZLWKRXWMXVWL¿FDWLRQ8VHWKHZRUG
³EHFDXVH ́ͼ௘RUVRPHHTXLYDOHQWYHUVLRQRILW௘ͽLQDOPRVWHYHU\VHQWHQFH\RXZULWHEHFDXVHWKLVZLOO
IRUFH\RXWRH[SODLQZK\HDFKFODLP\RXPDNHPXVWEHWUXH

A

B

E D C

x y z

Figure 8.2