Question

Calculate the angle marked y in
the diagram below.
by=||
57°
y

Answer 1

61.5

Explanation:

As the lines are parallel you can use the alternate angle rule.

So within the triangle you have 57 + x + x ( y is equal to the other angle because the lines are the same length and angle highlighted by the double lines )

And so...

180 - 57 = 123

123/2 = 61.5

Answer 2

Explanation:

2y+57=180

2y=180-57

2y=123

y=123/2=61.5°

y=61.5