In October, average temperatures at the base camp of Mount Everest are about (-10) degrees Celsius. Average temperatures during the same month at the summit of Mt. Everest are about (-27) degrees Celsius. About how many degrees warmer is it at the base camp?

1. statement- ca is parallel to db and e is the midpoint of ad reason- given2. statement- reason- alternate interior angles3. statement- de is congruent to ae reason- definition of midpoint4. statement- triangle aec is congruent to triangle deb reason- asa (angle side angle)