There is no information on the shape of the area in question.
18. The first ten composite numbers are: 4, 6, 8, 9, 10, 12, 14, 15, 16, 18
The composite factors of 72 are 4, 6, 8, 9, 12, 18, 24, 36, 72
The composite factors of 72 are 4, 6, 8, 9, 12, 18, 24, 36, 72
Composite. All positive, whole numbers greater than five and ending in 0, 2, 4, 5, 6 or 8 are composite.
They are: 4+6 = 10 and including 8 = 18
composite factors of 72 is 1 2 3 4 6 8 9 12 18 24 36 72
The 8th composite number is 15. The first 10 composite numbers are 4, 6, 8, 9, 10, 12, 14, 15, 16, 18.
They are: 8+9+10+12+14+15+16+18 = 102
54 is a composite number because it has 8 factors: 1, 2, 3, 6, 9, 18, 27, and 54.
11 numbers 2, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18 * * * * * NO! 2 is a prime, not a composite!
All even numbers - except 2 - are composite. Any number that ends with 0, 2, 4, 6, or 8 is even.
The numbers 4, 6, 8, 9, 10, 12, 14, 15, 16, 18 are the first ten composite numbers.