Quadrilateral ABCD is inscribed in this circle.

What is the measure of angle B?

Enter your answer in the box.
m∠B=

A quadrilateral inscribed in a circle. The vertices of quadrilateral lie on the edge of the circle and are labeled as A, B, C, D. The interior angle B is labeled as left parenthesis 4 x minus 20 right parenthesis degrees. The angle D is labeled as x degrees.

140 degrees

Explanation:

At this point, we know that opposite angles in quadrilaterals equal 180 degrees. The opposit angles in this particular quadrilateral is D and B

D+B=180

x+(4x-20)=180

5x-20=180

5x=200

x=40

Now, It asks for the measurement of angle B, not what X equals, so we plug it into the equation.

4x-20

4(40)-20

160-20=140

140 degrees

I hope this helped you out and I wish you good luck on the rest!

-Aspen

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