Question

this is my last question. someone help.

Answer 1

Calculate the area of both shapes

Answer 2

Yes, I got that. But I need help on getting there.

Answer 3

Cool. So, do you know how to calculate the area of a rectangle?

Answer 4

P= area of circle/area of rect.?

Answer 5

I think so.

Answer 6

in this problem, would the rectangle be 1.92?

Answer 7

Yep.
So A(rectangle) = base x height

\[and A(circle) = \pi r ^{2}\]

Answer 8

What do I do next?

Answer 9

Yep.
A(rectangle) = (1+1.4) x (0.8) = 1.92

Answer 10

So once you've got the area of the rectangle you need the area of the circle

Answer 11

It would be 0.5 because the radius is 0.4

Answer 12

Yeah
A(circle) = 0.4^2 x 3.1415...

Answer 13

So then, as you said, P= area of circle/area of rect
Simply calculate, using the values that we worked out

Answer 14

How do put that in equation?

Answer 15

P = (0.5) / (1.92)

Answer 16

0.26

Answer 17

.

Answer 18

Exactly

Answer 19

I have these other ones, all I need is someone to check if its right.

Answer 20

answer b

Answer 21

I agree

Answer 22

answer b.

Answer 23

@jayzdd is the last question correct?

Answer 24

you got b?

Answer 25

Yes

Answer 26

I'm guessing its wrong?

Answer 27

the circle has area pi * (.8/2)^2

Answer 28

the rectangle has three regions, the left of the circle region of the circle, the circle itself, and the right of the circle region

Answer 29

So what's the equation for it?

Answer 30

lets look at this square here http://prntscr.com/91dlno

Answer 31

it has total area 1.0 * 0.8 = .8
we want to find the probability of falling into
the area outside the semicircle

Answer 32

the semicircle area is 1/2 * pi * (.4)^2

the area to the left of the semicircle is
(1.0)*(.8) - 1/2 * pi * (.4^2)
divide this by total area (1.0)*(0.8)

Answer 33

So calculate (1.0)*(0.8) - 1/2 * pi * (0.4^2) first

Answer 34

we are trying to find the probability of falling into the green area
http://prntscr.com/91do6n

Answer 35

is the square of (0.4^2) meant to be inside or outside?

Answer 36

Do you agree that
green area + blue area = total area

Answer 37

Yes I got that

Answer 38

green area + blue area = total area

plugging in:
green area + 1/2* pi * (.4)^2 = 1.0 * (0.8)

solve for green area
green area = 1.0 * (0.8) - 1/2* pi * (.4)^2

Answer 39

Yes I got 0.54

Answer 40

probability of falling into green
= green area / total area
= .54 / ( 1.0 * 0.8)

Answer 41

actually its better if you keep more decimals
= .54867 / ( 0.8 ) = .6858
this rounds to .69

Answer 42

are we good?