Question

In a parallelogram Abcd , if angle a =(2x-30°) and angle d=(2x-10°) find angle b?​

Answer 1

Answer:

The measure of <B is 100°.

Step-by-step explanation:

Since the adjacent angles of a parallelogram are supplementary.

So,

=> <DAB + <ADC  = 180°

=> (2x - 30°) + (2x - 10°) = 180°

=> 2x + 2x - 30° - 10° = 180°

=> 4x - 40° = 180°

=> 4x = 180° + 40°

           220°

=> x = ----------

              4

=> x = 55°

So,

<D = (2x-10°) = 2 × 55° - 10° = 100°

Since <B is the opposite angle of <D. so the measure of these two angles are equal. So,

<B = 100°