I think the answer is 78 because more usually mean addition so 57+21=78
Answer:
The sum of interior angles of given polygon is 900°
Step-by-step explanation:
A regular polygon is a n-sided figure with n sides and the length of all sides is same.
In the diagram, we have a polygon with 7 sides.
The formula given is used to calculate the sum of interior angles of a polygon

Here n is the number of sides of polygon
In the given polygon
n = 7
So,

Hence,
The sum of interior angles of given polygon is 900°
Answer:
x=18, y= 6
Step-by-step explanation:
if x+y=24
x= 24- y
in second case
x= 3y
24_ y = 3y
24=4y
y= 6
hence x = 24 _6 = 18