When you name two congruent triangles with the letters of the vertices, you have to keep the order of the corresponding vertices. That means, that when you say triangle ABC is congruent to DEF, the corresponding congruent angles are A = D, B = E, and C = F. regarding the sides, segment AB = segment DE, segment BC = segment EF, and segment CA = segment FD. Then, the answer is that, of the four options,<span> the one that is not true is the option b, because as we already said the corresponding equal angle C is F, not E.</span>
C might be the correct answer try it :)
Okay, first, given the equation, we need to find out what the radius of the circle is. Let us state the general equation of a circle:
![\frac{(x-x_{1})^2}{r^2}+ \frac{(y-y_{1})_^2}{r^2}=1](https://tex.z-dn.net/?f=%20%5Cfrac%7B%28x-x_%7B1%7D%29%5E2%7D%7Br%5E2%7D%2B%20%5Cfrac%7B%28y-y_%7B1%7D%29_%5E2%7D%7Br%5E2%7D%3D1)
Where
![(x_{1}, y_{1})](https://tex.z-dn.net/?f=%28x_%7B1%7D%2C%20y_%7B1%7D%29)
is the centre of the circle. In this case, we don't need to know the centre. Just the radius.
Let us start by converting the equation into standard for, which I typed above. Divide both sides by 81.
![\frac{(x-3)^2}{81}+ \frac{(y+1)^2}{81}=1](https://tex.z-dn.net/?f=%20%5Cfrac%7B%28x-3%29%5E2%7D%7B81%7D%2B%20%5Cfrac%7B%28y%2B1%29%5E2%7D%7B81%7D%3D1)
Great! We now know the radius of the circle. It is
![\sqrt{81}](https://tex.z-dn.net/?f=%20%5Csqrt%7B81%7D%20)
because it is the bottom fraction. Now we know that the radius is 9.
So now lets input this into the area of circle formula:
Now we insert our radius.
You can convert that into a decimal if you wish.
Hope this helped!
~Cam943, Moderator
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Temp in city for weeks 1-4 = Starting temp - (20 deg C / 4 wk) * wk#
Temp in City for weeks 1-4 = starting temp - 5 deg c/wk * wk#
This shows the temperature in the city for weeks 1 2 3 4 given the original temperature of the city and whichever week you want to know from the starting point....week 1 week 2 week 3 week 4 .....