Answer: choice 2) SAS
AB = DE is one pair of congruent sides that forms the first S in SAS. The other S in SAS refers to the pair of congruent sides BC = EF. The A in SAS is the angle pair angle B = angle E. Note how angle B and angle E are between the two pairs of congruent sides. The order of the letters matters because SAS is different from SSA, which is not a valid congruence argument. Check out the attached image.
Answer:
Estimation is a mental process of coming up with an answer that is relatively close, to allow decisions to be made. The types of estimation are quantity, computation and measurement.
An estimation strategy is simply coming up with a good estimate based on evidence and already known facts. Coming to a conclusion as close to the real answer as you can. It can also be called an educated guess.
All we have to do is divide the distance of the old sidewalk by 3.14:
65 / 3.14 ≈ 20.7006
That means that, rounded to the nearest meter, the new sidewalk is:
21 meters long!
There we have an information of two functions 
Using this two functions
, we need to find the composition of functions (h\circ g)(t).
The composition of two functions h and g is the new function , by performing g first and then performing h.



Composition of h and g (t) = 

First plugin the value of 


We know that
, we need to find h(3t+3),
That is, to replace t by 3t+3,

Now distribute 2 into 3t+3,

Now plug in 


Thus the solution is (D).