Question

mes of each.
29. In figure, ZBO
B< 90° and AD I BC. Prove that
AC = AB + BC? - 2BC.BD​

Answer 1

Step-by-step explanation:

In the right angle triangle ABD, we have

AD² = AB² - BD²

In the right angle triangle ACD we have

AD² = AC² - CD²

So AC² - CD² = AB² - BD²

=> AC² = AB² + CD² - BD²

=> = AB² + (CD + BD)* (CD - BD )

= AB² + BC * [(BC - BD) - BD]

= AB² + BC * [ BC - 2 BD ]

= AB² +BC² - 2 BC * BD