The sum of an Arithmetic Series is given as:

where,
d = Common Difference = Difference of any two consecutive terms.
So,
d = 8
a1 = First term = 1
Using the values, we get:

The above equation gives the formula for n terms of an Arithmetic Series.
So, option A is the correct answer
Answer:
Mabel would have to draw a new angle that measured 97°.
Step-by-step explanation:
Supplementary angles always add up to 180°.
So, she would have to draw an angle that was
°
°
.
So Mabel would have to draw a new angle that measured 97°.
We can also say this in another way ... (8% of what number is 12?)
let a be the number of which 8 % is 12 ....
<span>8/100 x a =12 </span>
<span>a=12 x 100/8 </span>
<span>a=(6/4) x 100 </span>
<span>a=(3/2) X 100
a = 150 </span>
<span>now if u want to check your answer.. substitute the value of a .....</span>
<span>(8/100) x 150=12 ....
Hope it helps !!!</span>