Answer:
d
Step-by-step explanation:
y
Answer:
Option D. The student did not use the correct formula to calculate the area of the segment
Step-by-step explanation:
step 1
Find the area of the isosceles triangle
Applying the law of sines

step 2
Find the area of the sector
The area of the sector is 1/6 of the area of the circle
so

substitute the value

step 3
Find the area of the segment
The area of the segment is equal to the area of sector minus the area of triangle

therefore
The student did not use the correct formula to calculate the area of the segment
If the number is x, then 3 times x -20 >10 and 3x-20>10. Adding 20 to both sides, we get 3x >30 and by dividing by 3 we get x >10
The question is unclear to me, 30x3=10 WHAT, 30x3=90 not 10
And also it seems you already know the answer Perimeter=28cm
There is 20x more nonfiction than fiction so you do
20+1=21
so then to find out what

of 1155 is we do
1155÷21=55
so then we times 55 by 20 because there are 20x more nonfiction than fiction
55x20=1100
soo now we know there is
1100 nonfiction books and
55 fiction books
to check whether we are right we can do
1100=55=1155
we are right because there is 1155 books in the library
hope i helped