Answer:
Part A) The triangles ABC and EDC are similar by AAA, because the three internal angles are equal in both triangles
Part B) The width of the river is about 
Step-by-step explanation:
we know that
If two triangles are similar, then the ratio of its corresponding sides is equal and its corresponding angles are congruent
Part A) we know that
In this problem , triangles ABC and CDE are similar by AAA, because its corresponding angles are congruent
so
m<DCE=m<ACB -----> by vertical angles
m<EDC=m<ABC -----> is a right angle
m<DEC=m<CAB -----> the sum of the internal angles must be equal to 180 degrees
Part B) we know that
The triangles ABC and EDC are similar -------> see Part A
therefore

substitute the values and solve for AB


recycling the right things in the right places - for example, receipts cannot be recycled, and if they are out into paper recycling then this can often cause problems and a whole batch of paper to be recycled can be ruined. this means that a whole bunch of stuff has to go to waste.
Answer:
I believe this is true
Step-by-step explanation:
A)
Accurate = close to the 'true' value, and 9.998 is close to 10. Imagine a scale that has the zero point wrong as says 8.998, it would not be accurate, but still precise (several digits known)
Precise = several digits known. I would say to know it until grams is quite a good precision (the 9.998 has 4 digits)