The sum of the measures of the interior angles in a convex polygon is 1,260°. How many sides does the polygon have? A 5
B. 7
C. 9
D. 14

C

Step-by-step explanation:

The sum of the interior angles of a polygon is

sum = 180° (n - 2) ← n is the number of sides , thus

180 (n - 2) = 1260 ( divide both sides by 180 )

n - 2 = 7 ( add 2 to both sides )

n = 9

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer