Question

ABCD is a parallelogram in which ∠A =110°. Find the measure of each of the angles ∠B, ∠C and ∠D.

Answer 1

Since the sum of any two adjacent angles of a parallelogram is 180°,

∠A + ∠B = 180° 

110° + ∠B = 180° 

∠B = (180° - 110°) = 70° 

Also, ∠B + ∠C = 180° [Since, ∠B and ∠C are adjacent angles] 

70° + ∠C = 180° 

∠C = (180° - 70°) = 110°. 

Further, ∠C + ∠D = 180° [Since, ∠C and ∠D are adjacent angles] 

110° + ∠D = 180° 

∠D = (180° - 110°) = 70°. 

Therefore, ∠B = 70°, ∠C = 110° and ∠D = 70°.