Answer:
12.65
Explanation:
In the case of the blue triangle, to calculate the rise, which would be the increase, therefore it would be the hypotenuse formed by the arrow. 
We have to Pythagoras is: 
h ^ 2 = a ^ 2 + b ^ 2 
In this case: 
a (x-axis) = 4 
b (y-axis) = 12 
replacing: 
h ^ 2 = 4 ^ 2 + 12 ^ 2 
h ^ 2 = 160 
h = 12.65 
Which means that the rise in the blue triangle is 12.65 units