Okay I'll try to show it step by step

Step 1. So first you need to recognise that the diagram is a right angled triangle, with the right angle being at the bottom. This means we can do Pythagoras' Theorem.

Step 2. Now that you know you can use Pythagoras' Theorem, you can apply it. If you don't know, the theorem is a² + b² = c², with, in this case, a being 5 and b being 8. This means we can do 5² + 8² = 25 + 64 = 89.

Step 3. From the previous step, we now know that the length of the side including x is √89, and because we know that part of this side is 3, if we subtract 3 from √89 we get the value of x, so: √89 - 3 = 9.434 - 3 = 6.434, which is your answer.

I hope this helps!

5 0

3 years ago

The area of the shaded segment is 100cm^2. Calculate the value of r.

Reil [10]

Hello,

The formula for finding the area of a circular region is: $A= \frac{ \alpha *r^{2} }{2}$

then:
$A_{1} = \frac{80*r^{2} }{2}$

With the two radius it is formed an isosceles triangle, so, we must obtain its area, but first we obtain the height and the base.

$cos(40)= \frac{h}{r} \\ \\ h= r*cos(40)\\ \\ \\ sen(40)= \frac{b}{r} \\ \\ b=r*sen(40)$

Now we can find its area:
$A_{2}=2* \frac{b*h}{2} \\ \\ A_{2}= [r*sen(40)][r*cos(40)]\\ \\A_{2}= r^{2}*sen(40)*cos(40)$

The subtraction of the two areas is 100cm^2, then:

$A_{1}-A_{2}=100cm^{2} \\ (40*r^{2})-(r^{2}*sen(40)*cos(40) )=100cm^{2} \\ 39.51r^{2}=100cm^{2} \\ r^{2}=2.53cm^{2} \\ r=1.59cm$

Answer: r= 1.59cm

7 0

3 years ago

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