Which one of the following is an example of deductive reasoning? a) the first term of a sequence of numbers is 1, the second term is 3, and the third term is 5. thus, the nth term is 2n-1. b) the sum of the angles in which one of the following is an example of deduct and in which one of the following is an example of deduct is 180 degrees. therefore, the sum of the angles in any trianlge is 180 degrees. c) all rectangles have four right angles. since abcd is a rectangle, it must have four right angles. d) line l1 has a slope of 5 and line l2 has a slope of 4. line l1 is closer to the appearance of a vertical line than l2. thus, the larger the slope of a line, the more vertical the line will appear.