Answer:
Below.
Step-by-step explanation:
12. That is a semicircle
The central angle is 180 degrees.
Here we use the equation

Taking points (0,4), (1,2)
Substituting the point (0,4) , we will get

Substituting (1,2) we will get

So we have

Therefore , required equation is

Answer:
30
Step-by-step explanation:
We can ignore the fact they are similar altogether. It's known that all 3 angles of a triangle add up to 180, so:
180=102+48+m
180=150+m
30=m