Answer: First Option : Sₙ= n/2(a₁ + aₙ)
Step-by-step explanation:
The nth partial sum of an arithmetic sequence or the sum of the first n terms of the arithmetic series can be defined as the sum of a finite number of term in an arithmetic sequence.
It is calculated using the formula:
Sₙ= n/2(a₁ + aₙ)
Where :
a₁ = First term
aₙ = last term
n = number of terms
D! I’ve taken this
Please mark me as brainliest!
Circumference of a circle = 2πr
So,

Answer:
hexagon
Step-by-step explanation:
A hexagon has six vertices. Hope that this helps you and have a great day
[7×(-3)] × (-2)²
= (-21) × 4
= -84