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4 years ago

Area of a circle how do you do this

Mathematics

2 answers:

Katena32 [7]4 years ago

5 0

Answer:

See below.

Step-by-step explanation:

The area of the circle is given by the formula:

$A=\pi r^2$

From the circle, we can see that the diameter is 14. Thus, the radius must be 14 divided by 2 or 7.

We're also using 3.14 for π. Substitute:

$A=(3.14)(7)^2$

Use a calculator:

$A\approx153.86$

And we're done!

diamong [38]4 years ago

3 0

Answer:

153.86cm2

Step-by-step explanation:

so the number in the middle of circle is the circumference, you just need to divided by to to find the radius, the you plug in the values.

You might be interested in

Find the equation of the line . Write in slope intercept form and in standard form. (SHOW YOUR SOLUTION)

AlladinOne [14]

Answer:

1) The slope-intercept and standard forms are $y = -5\cdot x + 1$ and $5\cdot x +y = 1$ , respectively.

2) The slope-intercept form of the line is $y = \frac{5}{2}\cdot x -\frac{9}{2}$ . The standard form of the line is $-5\cdot x +2\cdot y = -9$ .

3) The slope-intercept form of the line is $y = \frac{5}{2}\cdot x + 5$ . The standard form of the line is $-5\cdot x +2\cdot y = 10$ .

4) The slope-intercept and standard forms of the family of lines are $y = \frac{2}{7}\cdot x -\frac{c}{7}$ and $2\cdot x -7\cdot y = c$ , $\forall \,c \in \mathbb{R}$ , respectively.

5) The slope-intercept form of the line is $y = 2\cdot x-7$ . The standard form of the line is $-2\cdot x +y = -7$ .

Step-by-step explanation:

From Analytical Geometry we know that the slope-intercept form of the line is represented by:

$y = m\cdot x + b$ (1)

Where:

$x$ - Independent variable, dimensionless.

$m$ - Slope, dimensionless.

$b$ - y-Intercept, dimensionless.

$y$ - Dependent variable, dimensionless.

In addition, the standard form of the line is represented by the following model:

$a\cdot x + b \cdot y = c$ (2)

Where $a$ , $b$ are constant coefficients, dimensionless.

Now we process to resolve each problem:

1) If we know that $m = -5$ and $b = 1$ , then we know that the slope-intercept form of the line is:

$y = -5\cdot x + 1$ (3)

And the standard form is found after some algebraic handling:

$5\cdot x +y = 1$ (4)

The slope-intercept and standard forms are $y = -5\cdot x + 1$ and $5\cdot x +y = 1$ , respectively.

2) From Geometry we know that a line can be formed by two distinct points on a plane. If we know that $(x_{1},y_{1})=(1,-2)$ and $(x_{2},y_{2}) = (3,3)$ , then we construct the following system of linear equations:

$m+b= -2$ (5)

$3\cdot m +b = 3$ (6)

The solution of the system is:

$m = \frac{5}{2}$ , $b = -\frac{9}{2}$

The slope-intercept form of the line is $y = \frac{5}{2}\cdot x -\frac{9}{2}$ .

And the standard form is found after some algebraic handling:

$-\frac{5}{2}\cdot x +y = -\frac{9}{2}$

$-5\cdot x +2\cdot y = -9$ (7)

The standard form of the line is $-5\cdot x +2\cdot y = -9$ .

3) From Geometry we know that a line can be formed by two distinct points on a plane. If we know that $(x_{1},y_{1})=(-2,0)$ and $(x_{2},y_{2}) = (0,5)$ , then we construct the following system of linear equations:

$-2\cdot m +b = 0$ (8)

$b = 5$ (9)

The solution of the system is:

$m =\frac{5}{2}$ , $b = 5$

The slope-intercept form of the line is $y = \frac{5}{2}\cdot x + 5$ .

And the standard form is found after some algebraic handling:

$-\frac{5}{2}\cdot x+y =5$

$-5\cdot x +2\cdot y = 10$ (10)

The standard form of the line is $-5\cdot x +2\cdot y = 10$ .

4) If we know that $a = 2$ and $b = -7$ , then the standard form of the family of lines is:

$2\cdot x -7\cdot y = c$ , $\forall \,c \in \mathbb{R}$

And the standard form is found after some algebraic handling:

$-7\cdot y = -2\cdot x +c$

$y = \frac{2}{7}\cdot x -\frac{c}{7}$ , $\forall \,c\in\mathbb{R}$ (11)

The slope-intercept and standard forms of the family of lines are $y = \frac{2}{7}\cdot x -\frac{c}{7}$ and $2\cdot x -7\cdot y = c$ , $\forall \,c \in \mathbb{R}$ , respectively.

5) If we know that $(x,y) = (3,-1)$ and $m = 2$ , then the y-intercept of the line is: