All categories

3 years ago

Find the area of a circle with diameter, d = 18m.Give your answer in terms of π.

Mathematics

2 answers:

Fofino [41]3 years ago

8 0

Answer:

81π

Step-by-step explanation:

Area of a circle formula is : $A=\pi r^2$ . r stands for radius.

Radius is half of the diameter. To solve for the area of the circle, we must replace r with diameter/2 which is 9 (18/2 = 9).

$A=\pi 9^{2}$

Now, the question wants us to give the answer in terms of pi. So we are going to simplify the equation WITH PI. Meaning, we aren't going to multiply pi. So we will just simplify 9 squared to 81.

So in terms of pi the area is 81π

Svetllana [295]3 years ago

6 0

Answer:

81π

Step-by-step explanation:

Area of a circle= π $r^{2}$ ( where r is the radius multiplying it twice)

Area of a circle = π × r × r ( this is the formula in simplier terms )

Area of a circle = 3.14 × 9 × 9 ( To get 9 divide 18 by 2 as diameter is 2 radii

Area of a circle = 81π ( multiply the numbers AND THESE ARE THE TWO NINES LEAVING π)

HOPE IT HELPED

You might be interested in

What is the scale factor from ALMN to AOPQ?

Nitella [24]

Answer:

Step-by-step explanation:

There 2 ways to interpret this problem.

From the info given:

These two triangles are congruent by SSS and congruent triangles have congruent or equal side lengths so the answer have to be 1.

If the triangles are similar, the side lengths form a proportion of that

$\frac{3}{3} = \frac{3}{3}$

So the ratio or scale factor is 1.

6 0

3 years ago

Prove that there is a positive integer that equals the sum of the positive integers not exceeding it. Is your proof constructive

Elena L [17]

Answer:

Constructive Proof

Step-by-step explanation:

Let x be a positive integer

x must be equal to sum of all positive integers exceeding it

i.e.

x = x + (x - 1) + ( x - 2) + ......... + 2 + 1

Equivalently,

x = ∑i (where i = 1 to x)

The property finite sum;

∑i (i = 1 to x) = x(x + 1)/2

So,

x = x(x + 1)/2 ------- Multiply both sides by 2

2 * x = 2 * x(x + 1)/2

2x = x(x + 1)

2x = x² + x ------- subtract 2x from both sides

2x - 2x = x² + x - 2x

0 = x² + x - 2x ----- Rearrange

x² + x - 2x = 0

x² - x = 0 ------ Factorise

x(x - 1) = 0

So,

x = 0 or x - 1 = 0

x = 0 or x = 1 + 0

x = 0 or x = 1

But x ≠ 0

So, x = 1

The statement is only true for x = 1

This makes sense because 1 is the only positive integer not exceeding 1

1 = 1

It is a Constructive Proof

A proof is constructive when we find an element for which the statement is true.

8 0

3 years ago

Simplify 4(x-y)-8(-7x+6y)

aliya0001 [1]

The answer is 60x-52y

Hope that helped!

8 0

3 years ago

Read 2 more answers

How do you find the percent change?

antoniya [11.8K]

Hello!!
To calculate the percentage increase: First: work out the difference (increase) between the two numbers you are comparing. Then: divide the increase by the original number and multiply the answer by 100. If your answer is a negative number then this is a percentage decrease.
let me know if u have anymore questions!:)

7 0

3 years ago

Find the measure of angle A. A 7x-1 12x 489

Degger [83]

Answer:

48 degrees

Step-by-step explanation:

7X-1+12x+48=180

19x+47=180

19x=133

x=7

7(7)-1=A

49-1=A

48=A

A is 48 degrees

7 0

3 years ago

Find the area of a circle with diameter, d = 18m.Give your answer in terms of π.​

Find the area of a circle with diameter, d = 18m.Give your answer in terms of π.