Answer:
<u> BC = 10 and AD = 30</u>
Step-by-step explanation:
In figure-1 , AB = CD ,BK ⊥ AD, AK = 10, KD = 20.
Since, line AD is sum of AK and KD, then
AD = AK + KD
AD = 10 + 20
AD = 30
Since, BC ║AD and BK ⊥ AD then similarly we construct CL ⊥ AD
so, BC = KL and AK = LD
KL = AD - LD
KL = 20 - 10
KL = 10
Since, BC = KL then BC = 10
Hence, <u> BC = 10 and AD = 30</u>