E - 30. From 6 to 9 is increase of 1.5times
- It's very long so I'm not giving answers but here's how i would do it:
- use Pythagoras
where c is the longest side - use sine rule
where lower cases are the sides, and capitals are their opposite angles.
e.g for 15:
a = 3, b is missing, c = 10
A is missing, B is ?, C is 90
I think its 8 but correct me if i am wrong.
The answer is letter A and letter D