This question uses Geotours Workbook E: Problem 12. Cinder Cones – S P Mountain, AZ. Fly to S P Mountain, AZ, and turn on the S P Mountain Contour Map overlay. The brown lines are contours (lines of equal elevations). Use the Ruler tool to determine the horizontal distance (ft) between the Problem 12 placemarks, and then subtract the elevations (ft) for each placemark from the contour map to determine the relief (vertical distance). Find the slope angle of S P Mountain using the following formula (this value is representative for many cinder cone volcanoes): slope angle = tan–1 (relief ÷ horizontal distance) Choose one: 5°–10° 15°–20° 25°–35° 35°–45°