6.2*10^-5 is the notation
The sum of 3 fifteens and 4 twos will be 45 +8 = 53
Most likely you are expected to recognize that side lengths 2, 3, 5 will result in a "triangle" of zero area (looks like a line segment).
The appropriate choice is
(5, 3, 2)
_____
Some authors write the triangle inequality as a + b ≥ c for any assignment of a, b, c to side lengths. The "or equal to ..." allows the triangle to have zero area (looks like a line segment). Other authors insist the inequality not include the "or equal to" case. It looks like your text's author is in the latter camp.
Answer:
Your answer for F will be 13.
Step-by-step explanation:
Take 11.2 and add it to 1.8, and you will get 13 and 13 will be the variable (f). So, f (13) - 1.8 = 11.2
Hope this helps! :D