Hello,
let's assume j the john's age, m the mary's age.
<span>"John is twice as old as mary"==>j=2*m
</span>
<span>"the sum of their ages is 21" ==>j+m=21
==>2*m+m=21
==>3m=21
==>m=7
and j=21-7=14
</span>
Answer:
The answer is 46 units
Step-by-step explanation:
You were correct in multiplying 12 by 4. However, you forgot to notice that the corners of every square were only shaded halfway. All you have to do then is subtract 48 by 2.
A = 1/4 * (pi) * d^2
A = 1/4 * (pi) * 8^2
A = 1/4 * (pi) * 64
A = 1/4(64) * (pi)
A = 64/4 * (pi)
A = 16 (pi) in^2
Your answer is 16 pi in^2
~Silver