Find the exact circumference of a circle with the given radius.

Mathematics

1 answer:

11Alexandr11 [23.1K]2 years ago

3 0

Answer:

$6.5\pi\ in$

Step-by-step explanation:

we know that

The circumference of a circle is equal to

$C=2\pi r$

we have

$r=3\frac{1}{4}\ in$

Convert to an improper fraction

$r=3\frac{1}{4}=\frac{3*4+1}{4}=\frac{13}{4}\ in$

substitute

$C=2\pi(\frac{13}{4})$

$C=\frac{13}{2}\pi=6.5\pi\ in$

You might be interested in

The points A BC :(2, 2,1), :(1,1,3), :(2,0,5) − are the vertices of a right triangle. The radius of the sphere with center at th

ElenaW [278]

Answer:

r=1

Step-by-step explanation:

First we need to know the length of each side of the triangle, so we use the formula of the vector modulus:

$|AB|= \sqrt{(b_{1}-a_{1})^{2}+(b_{2}-a_{2})^{2}+(b_{3}-a_{3})^{2}$

By doing so, we find:

$|AB|=\sqrt {6}\\|BC|=\sqrt {6}\\|AC|=2\sqrt {5}$

With this we know that the triangle is not right, but, we assume the longest side as the hypotenuse of the problem.

As we have two equal sides, we know that the line between point |AB| and the center of the hypotenuse is perpendicular, therefore, we can calculate it using Pythagoras theorem:

$|BC|^{2}=r^{2}+(\frac{|AC|}{2})^{2}\\\\r^{2}=|BC|^{2}-(\frac{|AC|}{2})^{2}\\\\r^{2}=(\sqrt{6})^{2}- (\frac{2\sqrt{5}}{2})^{2}\\\\r^{2}=6-5=1\\r=1$

4 0

2 years ago

3) For what price is 15 percent off the same as $75 off?

Kryger [21]

$\text{In this question, you would need to find the right value that 15\% is \$75}\\\\\text{You can do this by multiplying each number by 0.15}:\\\\200*0.15=30\\\\300*0.15=45\\\\350*0.15= 52.5\\\\500*0.15=75\\\\\text{You would see that 15\% of 500 is \$75}\\\\\boxed{\$500}$