Equation of an ellipse
→having center (0,0) , vertex (
and covertex
and focus
is given by:

As definition of an ellipse is that locus of all the points in a plane such that it's distance from two fixed points called focii remains constant.
Consider two points (a,0) and (-a,0) on Horizontal axis of an ellipse:
Distance from (a,0) to (c,0) is = a-c = 
Distance from (-a,0) to (c,0) is = a + c = 
a -c + a +c
= a + a
= 2 a →(Option A )
The sum of the interior angles of a polygon is (n-2)*180, n being the number of sides.
a nonagon has nine sides, so the total of interior angles is (9-2)*180=7*180
this is a regular nonagon, so each interior angle has the same degrees:
7*180/9=7*20=140
the exterior angle=180-the interior angle=180-140=40
40 is the correct answer.
Answer:
<h3>
x = 7 , y = 7√2</h3>
Step-by-step explanation:
The sum of measures of angles in triangle is 180°
so:
180° - 90° - 45° = 45°
two angles angles of the same measure, that means: x = 7
so:

Answer:
the number of adult ticket sold is 107 tickets
Step-by-step explanation:
The computation of the number of adult ticket sold is shown below:
Let us assume the number of tickets be x,
So, the adult be x
And for student it would be 3x
Students= 2x
Adults= x
Total = 4x
Now the equation could be
4x = 428
x = 107
This x signifies the adult tickets sold i.e 107
Hence, the number of adult ticket sold is 107 tickets