Question

In a trapezium ABCD, MC and MD are bisectors of angle C and angle D, respectively. Find angle ABC and angle BAD, if angle D=30 and angle C=40.

Answer 1

∠ABC=140° and ∠BAD =150°

Step-by-step explanation:

1. Given data

   ABCD is a trapezium.

   ∠ADC=30°

   ∠BCD=40°

2. In a trapezium ABCD

   AB is parallel to CD

3. We know that sum of co-interior angle of parallel line is 180°.

4. So

   ∠ABC+∠BCD =180°   (sum of co-interior angle of parallel line is 180°)

  ∠ABC+40° =180°

   ∠ABC =180°-40° =140°

5. From

   ∠BAD+∠ADC =180°   (sum of co-interior angle of parallel line is 180°)

  ∠BAD+30° =180°

   ∠BAD =180°-30° =150°