“Just follow your heart to find the answer” -someone
Answer:
125.6m^2
Step-by-step explanation:
Let R be the greater radius and r be the smaller radius
Area of the sidewalk = R^2 - r^2 - This can be the expression
= 3.14
=(R^2-r^2)
=(11^2-9^2)
=(121-81)
= 40
= 3.14 x 40
Using a calculator or a pencil, find each square root, including
three (3) decimal places. A negative number has no real square
roots, so skip '-71' and '-19'.
For each square root . . .
-- If the digits in the 2nd and 3rd decimal place are 00 through 24, then
make the 2nd decimal place a '0' and discard the rest.
-- If the digits in the 2nd and 3rd decimal place are 25 through 74, then
make the 2nd decimal place a '5' and discard the rest.
-- If the digits in the 2nd and 3rd decimal place are 75 through 99, then
increase the 1st decimal place by 1, make the 2nd decimal place a '0',
and discard the rest.
The area of a circle is A = πr^2. We let A1 And A2 the areas of the circles and r1 and r2 the radius of each, respectivley.
A1 + A2 = 80π
Substitute the formula for the area,
π(r1)^2 + π (r2)^2 = 80π
From the statement, we know that r2=2(r1).
<span>π(r1)^2 + π (2 x r1)^2 = 80π
</span>We can cancel π, we will have
5 x (r1)^2 = 80
Thus,
r1 = 4 and r2 = 8
Answer:
The answer is 21
Step-by-step explanation:
21x4+2=86
