Answer:
a+0 (or just 0)
Step-by-step explanation:
The additive identity is when you add any number by zero. This is because an additive identity is what number do you add to make the same number (since it's additive it is zero, if it were multiplicative, it'd be 1)
3x + 6 = 48 (alternate angles are equal)
- 6
3x. = 42
÷3
x = 14 degrees
180-48 - 2y + 5y-9 =180
123 + 3y = 180
-123
3y = 57
÷3
y = 19 degrees
Explanation:
To find the last angle on the top straight line, do:
180 - (the 2 given angles).
So, 180 - (3x + 16, which is 48 due to alternate angles being equal). Then, minus the 2y.
(180 - 48 - 2y) & simplify => 132 - 2y
This gives you the equation for the missing angle on our top straight line.
Thus, co-interior angles add to 180. So, we add the new equation (132 - 2y) to 5y - 9.
Simplify
=> 123 + 3y (because - 2+5 =3)
and put it equal to 180. Solve for y
Hope this helps!
Step-by-step explanation:
Alright, lets get started.
If the polygon measures 45 degree exterior angle and we are asked to find number of sides, there is a formula for that.
= value of exterior angle
Where n is number of sides of ploygon

Multiplying n into both sides


Now divide 45 in both sides

n = 8
Means number of sides of polygon is 8, hence its Octagon. Answer
Now we have given 45 exterior angle hence interior angle would be
180 - 45 = 135°
So, sum of all interior angles would be = number of sides * interior angle
sum of all interior angles would be = 
Hence sum of all interior angles would be 1080°. Answer
Hope it will help :)