Firstly, we have to realize that we cannot solve this problem without knowing the radius of the iris. because from the information given, the radius of the iris could well be the size of the galaxy and contract from width of 4mm to 2mm and we wouldn't know!

The average radius of the iris is 6mm, so we take this value.

Now, initially the width of the iris is 4mm, that means the radius of the pupil is:

$6mm-4mm=2mm$

Therefore it's area $A$ is:

$A=\pi r^2=\pi (2)^2=4\pi$

When the iris contracts to 2mm, the radius of the pupil becomes:

$6mm-2mm=4mm$

Then it's area is $A$ :

$A=\pi r^2=\pi (4)^2=16\pi$

To find how many times greater this final area is than the initial area, we just divide it by the initial area:

$\frac{16\pi }{4\pi } =4$

This is 4 times greater than the initial area.

3 0

3 years ago

Find the value of X, I need help solving this.

kykrilka [37]

Answer:

Step-by-step explanation:

add both expressions to equal 90 (bc of the right angle)- x+11+2x+1=90

when you solve, you get x=26

7 0

3 years ago

Read 2 more answers

What is the ratio of 65*3^17 to 65*3^14

solniwko [45]

<span>The ratio of 65*3^17 to 65*3^14 can be found as follows:

(65) (3^17) 65
--------------- = ----- * 3^(17-14) = 1 * 3^3 = 27 (answer)
(65) (3^14) 65</span>

3 0

3 years ago

Read 2 more answers

Name the postulate or theorem you can use to prove the triangles congruent

Lesechka [4]

Answer:

ASA

Step-by-step explanation:

if you understood the other, similar questions now, this one is really, really easy.

we got the confirmation for 2 angles and the side between these angles.

so, angle side angle or ASA

6 0

3 years ago