Answer:
1.25 miles
Explanation:
Check the image i uploaded.
You can form a right triangle with base b, height h ( the height of the mountain) and angle 12
for that one we can write
tan 12=h/b
for the triangle that has base 10+b, height h and angle 4.5 we write
tan 4.5= h/(10+b)
then we can solve both for h and equate
tan (12) *b= tan (4.5) (10+b)
solving for b you get b=5.88 miles. (remember to calculate trigonometric functions use a scienfitic calculator and be careful it is correclty set in degrees in this case)
Once you have b you can use any of the equations to calculate h
i'll use tan (12)*b=h=1.25 miles.