Respuesta :
Answer:
21 sides
Step-by-step explanation:
I don't know the right, but this is an alternative solution you can use also. Since a triangle's angles add up to 180, I kept multiplying 180. 180x7=1260. And 7x3=21 because a triangle has 3 angles
Answer:
9
Step-by-step explanation:
If the number of sides of the polygon is n, then
S=1260=(n−2)⋅180
Dividing both sides by 180, we obtain
7=n−2
which implies that n=9.
Therefore, this polygon has nine sides and is a nonagon.
