Answer:
71
Step-by-step explanation:
in a triangle all the angles together equal 180°. So all you have to do is add 43 + 66=109 and then subtract that from 180
Answer:
543
Step-by-step explanation:
Since we know that all angles in a triangle add up to 
, we can solve for 
and substitute it back into 
to find 
.
Remove the parentheses and combine like terms.
Add 
to both sides of the equation.
Divide both sides of the equation by .
Now that we have the value of , we can substitute it back into to find .
Answer:
3) 146 degrees
4) 471 degrees
5) x = 100 and 3x = 300
Step-by-step explanation:
all three are polygons whose sum of all interior angles can be found by using the formula (n - 2)*180 where 'n' refers to the number of sides
In #3 and 5 there are 5 sides, so (5 - 2)*180 = 3(180) giving a total of 540 degrees. Add all known angles and deduct from 540.
#4 has 7 sides, so (7 - 2)*180 = 1260 degrees. Add all known angles and deduct sum from 1260.
#5 Add all integers plus 'x' + '2x' to get 240 + 3x = 540
