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3 years ago

Please help with these two questions ASAP, will give BRAINLIEST!

Mathematics

2 answers:

algol133 years ago

7 0

Let me try my best to help you out :) ❤️

A) if the area of the square is 81, than that will mean that the length of all the sides are 9. You find the Perimeter by adding up all of the sides. So that will mean you do 9+9+9+9 which equals 36.

B) The diagonal that I got for the square is 12.728. The formula to find the diagonal is d=a sqrt 2.

Hope this helps!

OlgaM077 [116]3 years ago

3 0

Step-by-step explanation:

write what you know

square- all sides are equal

area of a square

A = L x W

where A = 81

L = sqrt(81)

W = sqrt(81)

perimeter the length around the square

P = sum of all sides

you can find hypotenuse using pythagorean thm

c=sqrt( L^2 + W^2)

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On a bicycle trail, the city is painting arrows like the one shown below:

mote1985 [20]

Answer:

151.5 cm^2

Step-by-step explanation:

lets cut stright acrros so you have a triangle 13 (base) by 3 cm (high)

area of a triangle is 1/2 base times hight --> 13x3/2 = 19.5cm^2

now lets doi the rectangle that is 12 by 11

Length times hight is the area is 132

add both areas 132 + 19.5

4 0

2 years ago

Please help worth 25 points

wariber [46]

Answer:

h=6 feet

Step-by-step explanation:

Given: 1. The base of a rectangle is three feet longer than its height.

2.Are of the rectangle=54 square meters

Let us say the rectangle has height h and base(breadth) b.

Since, the base of the rectangle is three feet longer than the height, we have b=h+3.

Also, Area of the Rectangle= hb

therefore, 54=h(h+3)

54= h2+ 3h

h2+3h-54=0 (Subtract 54 from both the sides)

To find the value of h we have to solve the quadratic equation.

[We have the equation in the form ax2+bx+c=0, to factorise the equation-

Step1. Find two numbers such that their multiplication is equal to ac and their addition is equal to b.

Step2. Replace b with these numbers.

Step3. Simplify the equation]

So, h2+3h-54=0

h2+9h-6h-54=0

h(h+9)-6(h+9)=0

(h+9)(h-6)=0

Which gives-

h= -9 or h= 6

As h is the height of the rectangle, h can not be -9.

so h=6 feet

and b=h+3=9 feet

So the dimensions of the rectangle are 6 feet for the height and 9 feet for the base.

5 0

2 years ago

The profile of the cables on a suspension bridge may be modeled by a parabola. The central span of the bridge is 1210 m long and

brilliants [131]

Answer:

The approximated length of the cables that stretch between the tops of the two towers is 1245.25 meters.

Step-by-step explanation:

The equation of the parabola is:

$y=0.00035x^{2}$

Compute the first order derivative of y as follows:

$y=0.00035x^{2}$

$\frac{\text{d}y}{\text{dx}}=\frac{\text{d}}{\text{dx}}[0.00035x^{2}]$

$=2\cdot 0.00035x\\\\=0.0007x$

Now, it is provided that |x | ≤ 605.

⇒ -605 ≤ x ≤ 605

Compute the arc length as follows:

$\text{Arc Length}=\int\limits^{x}_{-x} {1+(\frac{\text{dy}}{\text{dx}})^{2}} \, dx$

$=\int\limits^{605}_{-605} {\sqrt{1+(0.0007x)^{2}}} \, dx \\\\={\displaystyle\int\limits^{605}_{-605}}\sqrt{\dfrac{49x^2}{100000000}+1}\,\mathrm{d}x\\\\={\dfrac{1}{10000}}}{\displaystyle\int\limits^{605}_{-605}}\sqrt{49x^2+100000000}\,\mathrm{d}x\\\\$

Now, let

$x=\dfrac{10000\tan\left(u\right)}{7}\\\\\Rightarrow u=\arctan\left(\dfrac{7x}{10000}\right)\\\\\Rightarrow \mathrm{d}x=\dfrac{10000\sec^2\left(u\right)}{7}\,\mathrm{d}u$

$\int dx={\displaystyle\int\limits}\dfrac{10000\sec^2\left(u\right)\sqrt{100000000\tan^2\left(u\right)+100000000}}{7}\,\mathrm{d}u$

$={\dfrac{100000000}{7}}}{\displaystyle\int}\sec^3\left(u\right)\,\mathrm{d}u\\\\=\dfrac{50000000\ln\left(\tan\left(u\right)+\sec\left(u\right)\right)}{7}+\dfrac{50000000\sec\left(u\right)\tan\left(u\right)}{7}\\\\=\dfrac{50000000\ln\left(\sqrt{\frac{49x^2}{100000000}+1}+\frac{7x}{10000}\right)}{7}+5000x\sqrt{\dfrac{49x^2}{100000000}+1}$

Plug in the solved integrals in Arc Length and solve as follows:

$\text{Arc Length}=\dfrac{5000\ln\left(\sqrt{\frac{49x^2}{100000000}+1}+\frac{7x}{10000}\right)}{7}+\dfrac{x\sqrt{\frac{49x^2}{100000000}+1}}{2}|_{limits^{605}_{-605}}\\\\$