Which inequality explains why these three segments cannot be used to construct a triangle?

ef + fd > de
ed + ef < df
ed + ef > df
ef + fd < de

2 and 4

Step-by-step explanation:

The rule says that in any triangle , the sum of two sides is always greater than the third.

In our problem we see that , the first and third option holds true as they says the sum of the sides is greater than the third side.

But , on the other hand , the option 2 and 4 says , that the sum of the two sides is smaller than the third side. Which can not be possible.

Hence the inequality 2nd and 4th are false and we can not form a triangle with them.

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.