Answer:
Step-by-step explanation:
For this, both sides added together will need to equal 180°.
So you need to set up an equation: p+28+3p=180
Now, solve for p
p+28+3p=180
-28 . -28
p+3p=152
combine p (the single p counts as 1, so add it to 3p to get 4p)
4p=152
/4 . /4
p= 38
You get p is equal to 38.