Question

Find all the angles of a parallelogram if one angle is 80°.

Answer 1

Answer:

angle A= 80°

angle C = angle A ( opposite angles of a parallelogram are equal)

so angle C= 80°

angle A + angle D = 180° ( sum of adjacent angles of a parallelogram is 180° )

80°+ angle D = 180°

angle D= 180-80

angleD = 100°

angle D = angle B

therefore angle B = 100°

hope it helps..

Answer 2

QuestioN :

Find all the angles of a parallelogram if one angle is 80°.

GiveN :

• One angle = 80°.

To FiNd :

• Find all the angles of a parallelogram.

ANswer :

The angles of a parallelogram are:

∠A = 80°

∠B = 100°

∠C = 80°

∠D = 100°

SolutioN :

For a parallelogram ABCD, opposite angles are equal.

So, the angles opposite to the given 80° angle will also be 80°.

It is also known that the sum of angles of any quadrilateral = 360°.

So, if ∠A = ∠C = 80° then,

∠A + ∠B + ∠C + ∠D = 360°

Also, ∠B = ∠D

Thus,

80° + ∠B + 80° + ∠D = 360°

Or, ∠B +∠ D = 200°

Hence, ∠B = ∠D = 100°

Now, all angles of the quadrilateral are found which are:

∠A = 80°

∠B = 100°

∠C = 80°

∠D = 100°

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