There is no congruence between the triangles based on the given information. In general, two sides and an angle not between them are insufficient to specify the triangle completely. In this case, the angles that are congruent are adjacent to non-corresponding sides, so even if SSA correspondence were sufficient to ensure congruence, it would not be sufficient in this case.
The appropriate choice is
... none
Since we are given with the identity of the chemical as Carbon-14, we obtain the half-life of the chemical from a reliable source and get a value of 5730 years. The equation that we are going to use for this item is,
A(t)/A(0) = (0.50)^(n/5730)
where A(t) is the current amount, A(0) is the initial amount and n is the number of years. We know from the given that the ratio of A(t) and A(0) is equal to 0.63. Substituting this to the given,
0.63 = 0.50^(n/5730)
n = 3819.48
Thus, the sample is approximately 3819.5 years old.
3.73 rounded to the nearest whole number would be 4
The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope. (Atomic mass is also referred to as atomic weight, but the term "mass" is more accurate.)
I think so it is between 51~56%