Question

In fig angle CAB=90 and AD perpendicular to BC. if AC=13 cm and AB=10.3cm and BD=9cm. find AD

Answer 1

by paythagoras theorem
find the hypo
9-hypo
by geocentric mean
find ad
answer is ad=7.9

Answer 2

Step-by-step explanation:

Consider ΔBAC and ΔBDA,

∠CAB=90°=∠ADB

∠B=∠B(common)

∴ ΔBAC similar to ΔBDA ( AA similarity criterion )

∴ AB/BD = AC/AD ( corresponding sides of similar triangles are proportional )

     10.3/9 = 13/AD

      AD = 13 × 9 / 10.3

       AD = 117/10.3

        AD = 11.35cm.