Why are undefined terms necessary in geometry

The radius of a circle is 6. Using T, which equation expresses the ratio of the circumference of the circle to the circle's diam

Liono4ka [1.6K]

Answer:

Option (B)

Step-by-step explanation:

The given question is incomplete; here is the complete question.

The radius of a circle is 6. Using π, which equation expresses the ratio of the circumference of the circle to the circle's diameter?

A) C/6 = π

B) C/12= π

C) C = 6πr

D) C = 12πr

Formula to get the circumference of the circle is,

C = 2πr = π × D

Where C = circumference of the circle

D = Diameter of the circle

By dividing with D on both the sides of the formula,

$\frac{\text{C}}{\text{D}}=\pi$

Since, diameter 'D' = 2r,

$\frac{\text{C}}{\text{2r}}=\pi$

$\frac{\text{C}}{2\times 6}=\pi$

$\frac{\text{C}}{12}=\pi$

Therefore, equation given in Option (B) will be the correct expression.

5 0

3 years ago

Read 2 more answers

Pleasantburg has a population growth model of P(t)=at2+bt+P0 where P0 is the initial population. Suppose that the future populat

yulyashka [42]

Answer:

The population will reach 34,200 in February of 2146.

Step-by-step explanation:

Population in t years after 2012 is given by:

$P(t) = 0.8t^{2} + 6t + 19000$

In what month and year will the population reach 34,200?

We have to find t for which P(t) = 34200. So

$P(t) = 0.8t^{2} + 6t + 19000$

$0.8t^{2} + 6t + 19000 = 34200$

$0.8t^{2} + 6t - 15200 = 0$

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

$ax^{2} + bx + c, a\neq0$ .

This polynomial has roots $x_{1}, x_{2}$ such that $ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})$ , given by the following formulas:

$x_{1} = \frac{-b + \sqrt{\bigtriangleup}}{2*a}$

$x_{2} = \frac{-b - \sqrt{\bigtriangleup}}{2*a}$

$\bigtriangleup = b^{2} - 4ac$

In this question:

$0.8t^{2} + 6t - 15200 = 0$

So $a = 0.8, b = 6, c = -15200$

Then

$\bigtriangleup = 6^{2} - 4*0.8*(-15100) = 48356$

$t_{1} = \frac{-6 + \sqrt{48356}}{2*0.8} = 134.14$

$t_{2} = \frac{-6 - \sqrt{48356}}{2*0.8} = -141.64$

We only take the positive value.

134 years after 2012.

.14 of an year is 0.14*365 = 51.1. The 51st day of a year happens in February.

So the population will reach 34,200 in February of 2146.

6 0

3 years ago

Question:

aivan3 [116]

Answer:

part A) The scale factor of the sides (small to large) is 1/2

part B) Te ratio of the areas (small to large) is 1/4

part C) see the explanation

Step-by-step explanation:

Part A) Determine the scale factor of the sides (small to large).

we know that

The dilation is a non rigid transformation that produce similar figures

If two figures are similar, then the ratio of its corresponding sides is proportional

so

Let

z ----> the scale factor

$\frac{CB}{C'B'}=\frac{CD}{C'D'}=\frac{BD}{B'D'}$

The scale factor is equal to

$z=\frac{CB}{C'B'}$

substitute

$z=\frac{4}{8}$

simplify

$z=\frac{1}{2}$

Part B) What is the ratio of the areas (small to large)?

<em>Area of the small triangle</em>

$A=\frac{1}{2}(2)(4)=4\ units^2$

<em>Area of the large triangle</em>

$A=\frac{1}{2}(4)(8)=16\ units^2$

ratio of the areas (small to large)

$ratio=\frac{4}{16}=\frac{1}{4}$

Part C) Write a generalization about the ratio of the sides and the ratio of the areas of similar figures

In similar figures the ratio of its corresponding sides is proportional and this ratio is called the scale factor

In similar figures the ratio of its areas is equal to the scale factor squared

4 0

3 years ago

Helpp me pleasee (algebra)

antiseptic1488 [7]

Answer:

Step-by-step explanation:

answer = 1/2 r + m

m = 7

r = 8

answer = 1/2 * 8 + 7

answer = 4 + 7

answer = 11

8 0

3 years ago

sandra has 4 math test this marking period. she recieved 90%, 87%. and 92% on the first three. what is the minimum score she nee

Butoxors [25]

She would need to get a 90% or more.

6 0

3 years ago