Question

A polygon has 8 sides. What is the sum of its interior angles? use formula

Answer 1

S= (8-2) (180°)= (8-2)=6×180=1080 the answer is D.

Answer 2

The sum s for n=8 is
.. s = (8 -2)(180°)
.. s = 1080°

Selection D is appropriate.

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Put the number into the formula where the corresponding variable is, then do the arithmetic. A calculator can do the arithmetic for you, if necessary.