Perimiter
we have a half circle and 3 sides of a rectangle
half circle
circumfernce=2pir
half of that is 1/2 2pir or pir
so
diameter=8
radius is 1/2 of that or 4
so
that arc is 4pi
the 3 sides are 8+9+9 or 26
if we use pi=3.141592
4pi+26=38.566368
rounded we get
38.57
the closest one is C
answer is C
Answer:
its 26
Step-by-step explanation:
Notice that
13 - 9 = 4
17 - 13 = 4
so it's likely that each pair of consecutive terms in the sum differ by 4. This means the last term, 149, is equal to 9 plus some multiple of 4 :
149 = 9 + 4k
140 = 4k
k = 140/4
k = 35
This tells you there are 35 + 1 = 36 terms in the sum (since the first term is 9 plus 0 times 4, and the last term is 9 plus 35 times 4). Among the given options, only the first choice contains the same amount of terms.
Put another way, we have

but if we make the sum start at k = 1, we need to replace every instance of k with k - 1, and accordingly adjust the upper limit in the sum.


1/2 of 2 means you're taking a half of 2. Which 1.