All categories

3 years ago

99 POINTS

Mathematics

1 answer:

inysia [295]3 years ago

5 0

Answer:

Part a) The exact area of the sidewalk is $80\pi\ m^{2}$

Part b) The approximate area of the sidewalk is $251.2\ m^{2}$

Step-by-step explanation:

we know that

The area of the sidewalk is equal to the area of the outer circle minus the area of the inner circle

Part a) Find the exact area of the sidewalk

$A=\pi (12)^{2} -\pi (8)^{2}$

$A=\pi [144-64]$

$A=80\pi\ m^{2}$

Part b) Find the approximate area of the sidewalk

assume $\pi=3.14$

substitute

$A=80(3.14)=251.2\ m^{2}$

You might be interested in

How many tiles are added to each figure in the tile pattern shown above

DENIUS [597]

Answer:

4 tiles are added to each figure in the tile pattern.

6 0

3 years ago

Mary is preparing for her college entrance exams in a practice test she answered 12 problems in 30 minutes at this rate how many

kap26 [50]

Answer:

40 problems in 100 minutes

Step-by-step explanation:

This is a ratio problem.

You first divide 30 minutes by three to get how many problems she can do in 10 minutes. What you do to one side you do to the other side. So then, you should have 4 problems in 10 minute. Then, you multiply 10 by 10 and 4 by 10 to get 40 problems in 100 minutes.

6 0

3 years ago

What is the result of a dilation of scale factor 3 centered at the origin of the line 2y + 3x=10?? PLEASE HELP PLEASEEEEEEEEE

maks197457 [2]

Given:

The equation of a line is:

$2y+3x=10$

The line is dilated by factor 3.

To find:

The result of dilation.

Solution:

The equation of a line is:

$2y+3x=10$

For $x=0$ ,

$2y+3(0)=10$

$2y+0=10$

$y=\dfrac{10}{2}$

$y=5$

For $x=2$ ,

$2y+3(2)=10$

$2y+6=10$

$2y=10-6$

$2y=4$

Divide both sides by 2.

$y=\dfrac{4}{2}$

$y=2$

The given line passes through the two points A(0,5) and B(2,2).

If the line dilated by factor 3 with origin as center of dilation, then

$(x,y)\to (3x,3y)$

Using this rule, we get

$A(0,5)\to A'(3(0),3(5))$

$A(0,5)\to A'(0,15)$

Similarly,

$B(2,2)\to B'(3(2),3(2))$

$B(2,2)\to B'(6,6)$

The dilated line passes through the points A'(0,15) and B'(6,6). So, the equation of dilated line is:

$y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)$

$y-15=\dfrac{6-15}{6-0}(x-0)$

$y-15=\dfrac{-9}{6}(x)$

$y-15=\dfrac{-3}{2}x$

Multiply both sides by 2.

$2(y-15)=-3x$

$2y-30=-3x$

$2y+3x=30$

Therefore, the equation of the line after the dilation is $2y+3x=30$ .

3 0

3 years ago

Ive got a big maths test tomorrow ask me questions on fractions or percentages , formula , significant figures , Pythagoras anyt

podryga [215]

What 22/30 times 2/10

7 0

3 years ago

Find three consecutive even numbers whose sum is 96?

stepladder [879]

So consectuve even numbers

we know that one even number plus 2= another even number so we want to find 3 consecutive even numbers that add up to 96 or
x is the first number
x+2 is the second number
x+4 is the third number

x+x+2+x+4=96
3x+6=96
subtract 6 from both sides
3x=90
divide both sides by 3
x=30

the first number is 30
x+2=32=second number
x+4=34=third number

the numbers are 30,32,34

3 0

3 years ago

Read 2 more answers