Question

AB||DC,then angle ABC=?
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Answer 1

Answer:

60°

Step-by-step explanation:

Since the adjacent sides of trapezium are supplementry,

ADC + ABC= 180°.

3ABC = 180°

Also ABC =60°, BAD=60° And ADC=120° and CBA = 120°.

Draw a perpendicular DM bisecting AB, then triangle ADM is formed with DAM =60°. cos60 = 1/2= AM/AD

Hence AM/a=1/2 and AM=a/2.

Similarly the other side perpendicular CN is drawn and cos60 BN = a/2.

The remaining part is same as `b`.

AB = a/2 + a/2 + b = (a+b).

Answer 2

HELLO MATE

YOUR QUESTION IS:AB||DC,then angle ABC=?

Answer of your question is 90°

I hope this answer will help you

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