The sum of the alternate interior angles is equal to the angle given to you there. So basically, the sum of the angles INSIDE the triangle that aren't next to the outside angle are equal to that outside angle's measure. You already know that one of the angles is a right angle, which is equal to 90 degrees, so subtract that from the outside angle to get the measure of x. 122-90=x x=32
13 total; you must add the 5 he already hung in the morning plus, the 4 he hung in the afternoon; leaving you with 4 because 5 plus 4 is 9. 13 minus 9 is 4.
