The area of the base is given by: A1 = (1/2) * (15) * (13) A1 = 97.5 The area of the lateral faces is given by: A2 = (1/2) * (15) * (10) A2 = 75 Then, the total surface area is: A = A1 + 3A2 Substituting values: A = 97.5 + 3 * (75) A = 322.5 Answer: The surface area of the equilateral triangular pyramid is: C) 322.5 in2
We're told (and we can confirm) that , so is a linear combination of the other two vectors.
This means <em>H</em> is sufficiently spanned by ; no need for the third vector.
But this also means we can write either as a linear combination of , and as a lin. com. of . So any set of these three vectors taken two at a time will span the subspace <em>H</em>. Hence all of b, c, and d are acceptable.