Find the sum of the measures of the interior angles of a heptagon.

The exterior angles of a polygon add up to 360º in measure. For a regular heptagon, each exterior angle has an equal measure xº, so that 7xº = 360º, or xº ≈ 51.43º. Interior angles supplement exterior angles, so they each have measure 180º - xº ≈ 128.57º. Multiply this by 7 to get a total of 900º.

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !