Question

I need some help, please help. I have been stuck on this for days.

Answer 1

Answer:  155 degrees

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Explanation:

Angle B = 57 in the diagram is adjacent to angle ABC. The two supplementary angles add up to 180. This means angle ABC must be 180-57 = 123. Note how 57+123 = 180.

Line L is parallel to line M which means angle B = 57 is congruent to angle EAB because they are alternate interior angles.

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Focus on the pentagon ABCDE

We have the following interior angles

• A = 57 (aka angle EAB found earlier)
• B = 123 (aka angle ABC found earlier)
• C = 115
• D = unknown (what we want to solve for, since it's angle CDE)
• E = 90

For any pentagon, the interior angles always add to 540 degrees. Use the formula 180(n-2) and plug in n = 5 to get 540.

So we'll add up angles A through E and set that sum equal to 540

From there, we solve for D.

A+B+C+D+E = 540

57+123+115+D+90 = 540

D+385 = 540

D = 540-385

D = 155 degrees is the measure of angle CDE

Answer 2

Answer:

Angle CDE equals 155 degrees :D

Step-by-step explanation:

parallel lines

since the left angle is 57, angle BAE is also 57

180-57=123

right angle=90

115+90+123+57=385

540-385=155

thus, angle CDE equals 155 degrees