Question

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

Answer 1

Answer:

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 = ∠C

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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Hope it will be helpful:)

Answer 2

QUESTION -

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

ANSWER -

In a parallelogram, the opposite angles are equal while the adjacent angles are supplementary.

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With this property we can find all other angles if one is known.

The supplement of 80° is 100°.

One opposite pair is 80° each. Then the other pair will be 100° each.

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