Question

If Trapezium abcd, side ab parallel to side CD, diagonal achi and bd intersect at point of,. If ab 20cm , dc=6cm, ob=15cm , then find id

Answer 1

From the picture we have Δ COD is similar to Δ AOB.

Since, ∠COD=∠AOB (opposite angle) , ∠CDO=∠OBA (transversal angle)  and ∠DCO=∠OAB (transversal angle).

Then  

CD

/AB

= OD/OA

or,

 6/20 = OD / 15

OD = 4.5

 

 

Answer 2

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From the picture we have Δ COD is similar to Δ AOB.

Since, ∠COD=∠AOB (opposite angle) , ∠CDO=∠OBA (transversal angle)  and ∠DCO=∠OAB (transversal angle).

Then  

CD

/AB

= OD/OA

or,

6/20 = OD / 15

OD = 4.5

HOPE SO IT WILL HELP....