If a pentagon is regular, then all of the sides are the same length. This means that

So, if
, the lengths of the sides evaluate to

So, all the sides of the pentagon are 21 units long, and AB is 21 units long as well, because all sides are the same length.
Answer:
16°F
Step-by-step explanation:
15 + x = 31
x = 31 -15
x = 16
Answer:
Step-by-step explanation:instead, try making the subscripts and superscripts stand out:
n-1
a = a * r
n n-1
Believe me, it's worth the extra work to do this!!
Given the sequence -3, -6, -12, -24, you can easily see that the first term,
a is -3. The common factor is 2. Note how (-3)*2=-6, and so on.
1
So, a = -3 and r=2.
1
So the formula for this geometric sequence is
n-1
a = -3*2
n