For
(x-h)^2=4p(y-k)
vertex is (h,k)
distance from vertex to directix=p=distance from vertex to focus
|4p|=focal width
remember, focus is on the side of the parabola where it opens and directix is at the back
when p is negative, it opens down
when p is positive, it opens up
look at equation
-1/40(x-0)^2=(y-0)
times -40 to both sides
(x-0)^2=-40(y-0)
(x-0)^2=4(-10)(y-0)
vertex=(0,0)
p=-10,it's negative so it opens down
focus is 10 units below vertex (y direction)
focus=(0,-10)
diretix is 10 above
directix is y=10
focal width=|4p|=|4(-10)|=|-40|=40
vertex=(0,0)
focus=(0,-10)
directix is y=10
focal width=40 units
The measure of ∠FDE = 18°
<u>Explanation:</u>
A Pentagon has 5 sides and is made of 3 triangles
So, sum of the interior angles of the triangle = 180°
Therefore, the total interior angle of a regular pentagon = 3 X 180° = 540°
A regular pentagon will have all its angle equal
All the five angles would make 540°
Let the measure of one angle = x
So,
5x = 540°
x = 108°
Therefore, the measure of each angle of a pentagon is 108°
From the diagram,
∠AED + ∠FED = 180°
∠AED = 108° as it is one of the sides of the pentagon
So,
108° + ∠FED = 180°
∠FED = 72°
In ΔEFD,
∠FED + ∠EFD + ∠FDE = 180°
72° + 90° + ∠FDE = 180°
∠FDE = 18°
Therefore, the measure of ∠FDE = 18°
subtract 5 from both sides
Answer:
its a 13units
Step-by-step explanation:
