Question

The answer is 11 can someone tell me why?

Answer 1

Explanation:

to find the interior angles of a polygon, you must figure out 2 things: the number of angles, and what each measures

since there is 1620 for the angles and (n-2)180 = sum of int. angles, we can solve using this (n = the number of sides)

(n-2)180 = 1620

180n - 360 = 1620

180n = 1620 + 360

180n = 1980

1980/180 = n

n = 11 sides

Answer 2

The sum of interior angles is found by using the following equation:

∑ of interior angles = (S - 2)180

S = sides.

Note that the sum is given to you, or 1620. Plug in 1620 for the sum:

1620 = (S - 2)180

Next, isolate the variable, s. Note the equal sign, what you do to one side, you do to the other. Divide 180 from both sides:

(1620)/180 = ((S - 2)180)/180

S - 2 = 1620/180

S - 2 = 9

Next, isolate the variable, s. Add 2 to both sides:

S - 2 (+2) = 9 (+2)

S = 9 + 2

S = 11

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