Rhombus Angle Calculation: Finding Angle A When B = 80 Degrees

ABCD rhombus.

∢B=80 ∢B=80

Calculate the size ∢A ∢A

AAABBBDDDCCC80

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Step-by-step video solution

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00:00 Find angle A
00:08 In a rhombus, opposite angles are equal
00:26 The sum of angles in any quadrilateral equals 360
00:38 Let's substitute appropriate values
00:57 Let's collect terms and isolate A
01:23 And this is the solution to the problem

Step-by-step written solution

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1

Understand the problem

ABCD rhombus.

∢B=80 ∢B=80

Calculate the size ∢A ∢A

AAABBBDDDCCC80

2

Step-by-step solution

According to the properties of a quadrilateral, each pair of opposite angles are equal to each other.

Therefore:

B=C=80 B=C=80

A=D A=D

Additionally, we know that the sum of the angles in a quadrilateral equals 360 degrees.

Therefore, we can calculate angles A and D as follows:

360−80−80=200 360-80-80=200

200:2=100 200:2=100

Angle A is equal to 100.

3

Final Answer

100

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Indicates which angle is greater

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