Answer:
1) 
2) 
Step-by-step explanation:
1)
The two triangles are similar by AA similarity.
That means
.
We can add
to both sides to get
.
We can then subtract
from both sides to get
.
We know that the
because they both lie on a straight line.
We can plug in for
to get
.
We can divide both sides of the equation by
to get
.
We then add
to both sides to get
.
So,
and we're done!
2)
Because the two bases of a trapezoid are parallel, meaning adjacent top and bottom angles sum to
, we have that
.
We can subtract a
and an
from both sides to get
.
We then divide both sides of the equation by
to get
.
We do the same thing for
. On the other side of the trapezoid, we have that
.
We combine like terms on the left side to get
.
We subtract a
from both sides to get
.
We divide both sides of the equation to get
.
So,
and we're done!