To get the sum of the measures of the interior angles of a polygon, use (n - 2) ·180. N is the number of sides the polygon has.
A decagon has 10 sides. Plug 10 in for n.
(10 - 2) · 180
8 · 180 = 1,440
The interior angles in a decagon add up to 1,440°.
F) 1,440