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Aneli [31]
3 years ago
15

If arc EF = 151°, find mEDF.

Mathematics
1 answer:
user100 [1]3 years ago
4 0
There is a theorem that says that this angle (formed by thre points on the circumference) is half such arc called EF.

We can deduct it as well.

1) Call O the center of the circle. The central angle (EOF) = arc EF = 151°

2) Draw a chord from F to D and other chord from D to E.

You have constructed two triangles, FOD and DOE.

3) Triangle FOD has two sides equals (because both are the radius of the circcle). Then, this is an isosceles triangle and it has two angles of the same measure. Call this measure a.

4) Triangle DOE is also isosceles, for the same reason explained in the poiint 3. Call the measure of its equal angles b.

5) The sum of the angles of the two triangles is 180° + 180 ° = 360°.

This is a + a + b + b + (360 - central angle) = 360°

=> 2a + 2b = central angle
=> 2(a+b) = cantral angle
=> (a+b) = central angle / 2 = 151° / 2 =71.5°

(a+b) is the angle that you are looking for.

Then the answer is 71.5°

 
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In 2013 number of students in a small school is 284.it is estimated that student population will increase by 4 percent
BaLLatris [955]

The situation can be modeled by a geometric sequence with an initial term of 284. The student population will be 104% of the prior year, so the common ratio is 1.04.

Let \displaystyle PP be the student population and \displaystyle nn be the number of years after 2013. Using the explicit formula for a geometric sequence we get

{P}_{n} =284\cdot {1.04}^{n}P

n

=284⋅1.04

n

We can find the number of years since 2013 by subtracting.

\displaystyle 2020 - 2013=72020−2013=7

We are looking for the population after 7 years. We can substitute 7 for \displaystyle nn to estimate the population in 2020.

\displaystyle {P}_{7}=284\cdot {1.04}^{7}\approx 374P

7

=284⋅1.04

7

≈374

The student population will be about 374 in 2020.

5 0
2 years ago
There were 40 fingers total on the number of gloves Mrs. Edwards knitted. How many gloves did Mrs.Edward knit.
GarryVolchara [31]
40 ÷10 = 4

Mrs Edward knitted 4 pairs of gloves.
7 0
3 years ago
Read 2 more answers
The equation of a circle is x2 + y2 + Cx + Dy + E = 0. If the radius of the circle is decreased without changing the coordinates
valkas [14]

Answer:

Option E

Step-by-step explanation:

The standard equation of circle is:- (x-h)² + (y-k)² = r²

where (h,k) is center point and r is radius

If radius r is decreased then also (h,k) remains same, only r² increases

Equation given in question is x² + y² + Cx + Dx + E=0

So, C and D will remain same but E will increase

4 0
3 years ago
How do I find the correct answer
lys-0071 [83]

I think it is a because it shows us the points that the students made. I also think it is d. But I think it is mainly a.

-Dhruva;)

3 0
3 years ago
Pls can someone pls help me <br> Please show your work
Lana71 [14]

Answer:

x = 8

I dunno what the question is in the first place, but I assume you are solving for x.

Step-by-step explanation:

The two given angles are equivalent because they are parallel and they have a line that intersects.

The line creates two angles on each side of each line, which is 120 or 60 because there are 180 degs on a straight line.

The obtuse side is 120, and the -8 + 16x is also on an obtuse angle, showing that they are equal.

120 = -8 + 16x

128 = 16x

8 = x

x = 8

7 0
2 years ago
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