Answer:
Through the period luminosity relation to Cepheid variables
Explanation:
The luminosity of a given Cepheid can be established when the period luminosity relationship is calibrated.
Their brightness is then used to find their distance
Answer:
we know that sum of all angles of triangle is 180
let angles be 5x , 6x , 7x
now sum of angles : 5x + 6x + 7x = 18x = 180
therefore we got x : 10
therefore angles : 50 , 60 , 70
by Serial killer....
B. British because as you can see that the French greek and Hungarian don't cross Croatia Serbia or romania