8.
(i) If one of the angles of a parallelogram measures 75°, find the other angles.
Answers
Answer:
75 degrees, 105 degrees and 105 degrees
Step-by-step explanation:
Here is a parallelogram.
In a parallelogram, opposite angles are congruent (the same value). As pictured the angles diagonal of each other are the same value.
Additionally, angle A and angle B must add up to be 180 degrees.

So here is a parallelogram that we can use to solve the problem.

So let’s set angle A as our given value.
angle A= 75 degrees
So therefore, angle C = 75 degrees because we know that opposite angles are congruent.
Then, we make an equation to find angle B.
Angle A + Angle B = 180 degrees
We know this because of the properties of a parallelogram.
So, plug and chug.
75 degrees + angle B = 180 degrees
(subtract 75 from both sides)
angle B = 105 degrees
And we also know that angle D = 105 degrees because opposite angles are congruent.
So, the measurements of the other angles are 75 degrees, 105 degrees and 105 degrees.