In parallelogram ABCD m
pleaes help me
What is the sum of the measures of the angles of a quadrilateral?
i have 114
Is that the answer to the problem, or the answer to my question?
i dont know
You wrote "I have 114." Where did that come from?
i added the two langles i have together
Is 83 + 34 = 114?
yes
Ok, let's do this. I asked a question above, not to bother you, but because it is part of the solution of the problem. There are several things you need to know to solve this problem.
1. The sum of the measures of the angles of a polygon is 180(n - 2) where n = number of sides.
In your case, you have a parallelogram. A parallelogram has 4 sides, so n = 4. We use the formula with n = 4: 180(n - 2) = 180(4 - 2) = 180(2) = 360 The sum of the measures of the angles of a parallelogram is 360. Ok so far?
okay i kinda understand that
2. Another thing you need for this problem. In a parallelogram, opposite angles are congruent. Remember congruent angles are angles that have the same measure. |dw:1467389912173:dw|
Look at the figure above. Quadrilateral ABCD is a a parallelogram. Since angle A measures 120 deg, then the opposite angle, and C must also measure 120 deg. Ok so far?
ok
Since opposite angles are congruent, angles A and C are congruent and have the same measure. If angle A measures 120 deg, then angle C also measures 120 deg. This allows us to find the measures of angles B and D. Angles B and D are opposite angles in a parallelogram, so they have the same measure. Since all angles of a parallelogram add up to 360 degrees, subtract 120 for angle A and 120 for angle C, and you have 360 - 120 -120 = 120. Angles B and D add up to 120 deg and have the same measure, so angles B and D both measure 60 degrees.
This means that once you know the measure of one angle of a parallelogram, you can find the measures of the other three angles.
okay i understand that but how did you find the 3 one
3. You need to use alternate interior angles of parallel lines. |dw:1467390494419:dw|
i get that
|dw:1467390592272:dw|
x would be 34
Sides BC and AD are parallel. That is part of the definition of a parallelogram. What is the measure of angle x? (Hint: use alternate interior angles.)
Wow, you answer before I ask.
|dw:1467390715526:dw|
i kinda figured you would ask
i just cant see how you get the other one
Now that we know that that angle above is 34, we add 34 and 83 to get the measure of the entire angle of the parallelogram. What is 83 + 34? (Hint: it is not 114.) (Notice the last digits 3 and 4 add to 7 not to 4.)
117
Much better. Now this is the problem we have. |dw:1467390843416:dw|
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