What are the units of your 28.5 number? And of your elevation? And the 3.0 ? Is the latter degrees?
You can't do physics without including dimensions with your numbers.
This appears to be basically a trig problem. Use the definition of the tangent of an angle.
When driving west toward the Rocky Mountains, you see a peak 3.0 above the horizon. Your GPS gives your current elevation as 1630 , and according to the map, you're 28.5 (horizontally) from the peak.
Find the peak's elevation
3 answers
Sorry it is 28.5m horizontally from the peak. You see a peak at 3.0 degrees, and the current eleevation is 1630 meters.
Elevation (in meters) = 1630 + 28,500 tan 3.0
= 3124 m
= 3124 m