Question

in ∆ABC ,<ABC= 90°, and BD is perpendicular to the AC.if AD=4 cm and CD=5 cm then BD=?​

Answer 1

Step-by-step explanation:

In triangle ABC & ADB

/_ A = /_A (common)

/_ABC = /_ ADB (each 90)

Therefore Triangle ABC similar to Triangle ADB

=> AB/AD = AC/AB

=> AB2= AD x AC

=> AB2= 4 x 9 (AC=AD+CD = 4+5 = 9 cm)

=> AB2= 36

=> AB = 6 cm

In Triangle ABD using Pythagoras Theorem

AB2= AD2+ BD2

62 = 42 + BD2

BD2= 36 - 16 = 20

BD = 2√5

Answer 2

$\cos( \tan( \tan( \cot( \beta etr) ) ) ) \beta \gamma \alpha$