Answer:
The third exterior angle is 
Step-by-step explanation:
Given


Required
The third exterior angle 
The exterior angles of a triangle add up to 360 degrees.
So:

Make
the subject

Substitute known values


Answer:
∠B ≅ ∠Y △ABC ~ △ZYX by the SAS similarity theorem.
Step-by-step explanation:
1.
units
units
units
units, then

2.
and
are right angles - given
3.
two right angles are always congruent.
4.
by SAS similarity theorem.
SAS Similarity Theorem states that if two sides in one triangle are proportional to two sides in another triangle and the included angle in both are congruent, then the two triangles are similar.
Answer:
Part A) 
Part B) 
Part C) 
Step-by-step explanation:
Part A) we know that
In the right triangle ABC of the figure the sine of angle A is equal to divide the opposite side angle A by the hypotenuse
so

substitute the values

Part B) we know that
In the right triangle ABC of the figure the cosine of angle A is equal to divide the adjacent side angle A by the hypotenuse
so

substitute the values

Part C) we know that
In the right triangle ABC of the figure the tangent of angle A is equal to divide the opposite side angle A by the adjacent side angle A
so

substitute the values


This is an exact answer. the answer will be a bit larger than 20
Outcome
Hope this helps :)