C) isosceles; since a rhombus always has 4 equal sides, each triangle must have 2 equal sides.
Explanation<span>:
A rhombus does have 2 acute angles and 2 obtuse angles. If you draw the diagonal from one obtuse angle to the other, then each triangle would have all acute angles and be acute triangles.
However, if you draw the diagonal from one acute angle to the other, then each triangle would have an obtuse angle, and be obtuse triangles.
The length of the diagonal does not have to equal the length of the sides, so the triangles will not necessarily be equilateral.
However, no matter where you draw the diagonal, you will have two congruent sides in each triangle (the sides of the rhombus that form the triangle). Thus the correct answer is C).</span></span>
