All categories

3 years ago

Find the area of the circle with diameter 19.4 cm to the nearest tenth. Use 3.14 for π. *

Mathematics

2 answers:

Vlad1618 [11]3 years ago

8 0

i think the answer is A

Amiraneli [1.4K]3 years ago

5 0

19.4 divided by 2, to find the radius. Then square it, and then multiply it by pi. Which gives you A as the answer

You might be interested in

If the endpoints of the diameter of a circle are (−8, −6) and (−4, −14), what is the standard form equation of the circle?

kondaur [170]

Equation of the circle is $(x+6)^{2}+(y+10)^{2}=20$ .

Solution:

The endpoints of the diameter of a circle are (–8, –6) and (–4, –14).

Center of the circle = Mid point of the diameter

Mid point formula:

$$P(x, y)=\left(\frac{x_{1}+x_{2}}{2}, \frac{y_{1}+y_{2}}{2}\right)$

Here, $x_1=-8, y_1=-6, x_2=-4, y_2=-14$

$$P(x, y) =\left(\frac{-8-4}{2}, \frac{-6-14}{2}\right)$

$$P(x, y) =\left(\frac{-12}{2}, \frac{-20}{2}\right)$

$$P(x, y) =(-6, -10)$

Center of the circle = (–6, –10)

Radius is the distance between center and any endpoint of the diameter.

To calculate the radius using distance formula.

$r=\sqrt{\left(x_{2}-x_{1}\right)^{2}+\left(y_{2}-y_{1}\right)^{2}}$

Here, $x_1=-6, y_1=-10, x_2=-8, y_2=-6$

$r=\sqrt{\left(-8-(-6)\right)^{2}+\left(-6-(-10)}\right)^{2}}$

$r=\sqrt{(-8+6)^{2}+(-6+10)^{2}}$

$r=\sqrt{(-2)^{2}+(4)^{2}}$

$r=\sqrt{20}$ units

The standard form of the equation of a circle is

$(x-a)^{2}+(y-b)^{2}=r^{2}$ , where (a, b) are center and r is the radius.

Here, center = (–6, –10) and $r=\sqrt{20}$

$(x-(-6))^{2}+(y-(-10))^{2}={(\sqrt{20})} ^{2}$

$(x+6)^{2}+(y+10)^{2}=20$

Equation of the circle is $(x+6)^{2}+(y+10)^{2}=20$ .

4 0

3 years ago

2×-20/3 =2x help me please

Llana [10]

Answer:

x = - 5

Step-by-step explanation:

Given

$\frac{2x-20}{3}$ = 2x ( multiply both sides by 3 to clear the fraction )

2x - 20 = 6x ( subtract 2x from both sides )

- 20 = 4x ( divide both sides by 4 )

- 5 = x , that is x = - 5

4 0

3 years ago

The rent for an apartment was $6,600 per year in 2012. If the rent increased at a rate of 4% each year thereafter, use an expone

yan [13]

Answer:

$8,029.91

Step-by-step explanation:

You have to use the exponential growth equation:

A=P(1+r)^t

Where A is the final amount, P is the initial amount, r is the rate of increase, and t is the time in years. So:

A=6,600(1+0.04)^5

(The rate has to be changed into a decimal)

Then, just plug this equation into a calculator (without the A= part, so just 6,600(1+0.04)^5) and you'll get the answer.

8 0

3 years ago

What is the modulus after (-1+sqrt3i) gets raised to the 6th power

Eddi Din [679]

Answer:

it is b

Step-by-step explanation:

took the test

8 0

3 years ago

Read 2 more answers

Factor -7x = 21x2 = 3x - 9 by grouping

Verdich [7]

The correct answer is Zero

6 0

3 years ago