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3 years ago

How do i find the circumference and area of a circle

Mathematics

2 answers:

mote1985 [20]3 years ago

8 0

C = $\pi d$
a = $\pi r^{2}$
r = radius and d = diameter.

Anika [276]3 years ago

5 0

Answer:

C = πd

The area of a circle can be found by multiplying pi ( π = 3.14) by the square of the radius.

If a circle has a radius of 4, its area is 3.14*4*4=50.24.

If you know the diameter, the radius is 1/2 as large.

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Anura found a can of paint that was full. She was able to paint 3 fence posts with the paint. What fraction of the can of paint

Aleksandr-060686 [28]

She used 1/3 of of the paint can on a single fence post

5 0

3 years ago

Read 2 more answers

This question is from the similarity chapter. It would be really kind of you if you would answer this question.

katen-ka-za [31]

Answer:

a) 1650 m

b) 1677.05 m

Step-by-step explanation:

Hi there!

1) Determine what is required for the answers

For part A, we're asked for solve for the horizontal distance in which the road will rise 300 m. In other words, we're solving for the distance from point A to point C, point C being the third vertex of the triangle.

For part B, we're asked to solve for the length of the road, or the length of AB.

2) Prove similarity

In the diagram, we can see that there are two similar triangles: Triangle AXY and ABC (please refer to the image attached).

How do we know they're similar?

Angles AYX and ACB are corresponding and they both measure 90 degrees
Both triangles share angle A

Therefore, the two triangles are similar because of AA~ (angle-angle similarity).

3) Solve for part A

Recall that we need to find the length of AC.

First, set up a proportion. XY corresponds to BC and AY corresponds to AC:

$\frac{XY}{BC}=\frac{AY}{AC}$

Plug in known values

$\frac{2}{300}=\frac{11}{AC}$

Cross-multiply

$2AC=11*300\\2AC=3300\\AC=1650$

Therefore, the road will rise 300 m over a horizontal distance of 1650 m.

4) Solve for part B

To find the length of AB, we can use the Pythagorean theorem:

$a^2+b^2=c^2$ where c is the hypotenuse of a right triangle and a and b are the other sides

Plug in 300 and 1650 as the legs (we are solving for the longest side)

$300^2+1650^2=c^2\\300^2+1650^2=c^2\\2812500=c^2\\1677.05=c$

Therefore, the length of the road is approximately 1677.05 m.

I hope this helps!

3 0

3 years ago

Emma is planning a surprise party. she is considering.......

Ann [662]

Answer:

Step-by-step explanation:

what is she considering? I would need more information to complete the probolem

5 0

2 years ago

Read 2 more answers

Evaluate -3x+4y when x=-7 y=-10

Alexus [3.1K]

Answer:

-19

Step-by-step explanation:

6 0

3 years ago

the length of a rectangular garden is 3 m greater than the width. The area of the garden is 70m squared. find the dimensions of

Lerok [7]

A = l x w

so you know that the length is 3m longer than the width, so you could use a formula to represent that

w = l + 3

you then substitute the second equation into the first to solve for l

70 = l x (l +3)
70 = l^2 + 3l

you could then rearrange the formula and solve for l using the quadratic formula

0 = l^2 + 3l - 70

l = -3 +- (square root (3)^2 - 4(1)(70)) / 2(1)
l = -3 +- (square root 9 + 280) / 2
l = -3 +- (square root 289) / 2
l = -3 +- 17 / 2

then you solve for the two seperate roots

l = -3 + 17 /2
l = 14 / 2
l = 7

or

l = -3 - 17 / 2
l = -20 / 2
l = -10

since a length cannot be negative, this root is not viable. therefore l = 7

to solve for w you would use

w = l + 3
w = 7 + 3
w = 10

hope this helps! if you did not understand a step or concept please let me know!

4 0

3 years ago