ABCD is a trapezoid.
Calculate the size of angle .
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ABCD is a trapezoid.
Calculate the size of angle .
The sum of angles in a trapezoid is 360 degrees.
Therefore:
Let's substitute the known data into the above formula:
We'll move terms and maintain the appropriate sign:
50
Indicates which angle is greater
A trapezoid has 4 sides, making it a quadrilateral! Only triangles have angles that sum to 180°. Any 4-sided shape (square, rectangle, parallelogram, trapezoid) always has interior angles totaling 360°.
Not at all! The method works the same way: subtract the sum of known angles from 360°. Whether you're finding angle A, B, C, or D, the process is identical.
Check your arithmetic! In this problem, if you get something like 130° or -50°, you likely made an addition error. Interior angles in quadrilaterals are typically between 10° and 350°.
Yes! The angle sum property works for any quadrilateral - square, rectangle, parallelogram, rhombus, or irregular four-sided figure. They all sum to 360°.
Add all four angles together: they should equal exactly 360°. Also, each individual angle should be positive and less than 180° for a convex quadrilateral like this trapezoid.
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