Question

A circular disc has an area that measures between 1,650 and 1,700 square inches. What could be the length of its radius? Use 3.14 for pi.
A.23 in.
B.24 in.
C.25 in.
D.26 in.

Answer 1

Well if it was exactly 1,650 it would be 22.9174892211877 or 22.917. If it was exactly 1,700 it would be 23.2621324584064 or 23.262.

Now to find our answer :

(Our observations)

• there is no 22
• there is only one number that is less than 23.262

Answer our question : From our observations we now can say that our answer is 23 inches because it is between 22.917 and 23.262.

Hoped I helped!

Answer 2

we know that

the area of a circle is equal to

$A=\pi r^{2}$

where

r is the radius of the circle

Step 1

Find the radius for $A=1,650\ in^{2}$

$A=\pi r^{2}$

Solve for r

$r=\sqrt{\frac{A}{\pi}}$

substitute the value of area

$r=\sqrt{\frac{1,650}{3.14}}=22.92\ in$

Step 2

Find the radius for $A=1,700\ in^{2}$

$A=\pi r^{2}$

Solve for r

$r=\sqrt{\frac{A}{\pi}}$

substitute the value of area

$r=\sqrt{\frac{1,700}{3.14}}=23.27\ in$

therefore

the radius r

$22.92\ in \leq r \leq 23.27\ in$

the answer is the option A

$23\ in$