You could take it from either of the non-right angles.
To one angle, which side is opposite and which is adjacent is different than to the other angle. This is also why sin(x) = cos(90-x) and cos(x) = sin(90-x).
<span>281.6.................................if my calculations are right wich the are. all the time</span>
C. Triangle
Because...
This shape is a right rectangular pyramid, which has a base of a rectangle and sides in the shape of triangles; thus, a vertical cut would make a triangle.
Constructing What? you did not finish the question
21+-3 so 18 to 24 is the answer