Answer:
A. 10
Step-by-step explanation:
As we know that
The length of the major axis of the ellipse is 10
i.e
2 a = 10
Also, the ellipse is the curve that consists of 2 focal points in order that the total of the distance to the 2 focal points would remain constant for each and every point displayed in the curve
Now we assume that P is the curve point
So,
PF1 + PF2
i.e
2 a (blue line) + (red line)
2 a = 10
Therefore the sum of the length is 10