Question

Parallelogram ABCD has the angle measures shown. Can you conclude that it is a rhombus, a rectangle, or a square? Explain.

a. Parallelogram ABCD is a square, because all four angles have the same measure.
b. There is not enough information.
c. Parallelogram ABCD is a rhombus, because the diagonal bisects two angles.
d. Parallelogram ABCD is a rectangle, because the diagonal creates congruent angles.

Answer 1

Explanation:

Refer the attached figure :

In Δ ABD ,

∠B=∠D = 66°

By property : opposite sides of equal angles are equal

Thus AB=AC

In Δ CBD ,

∠B=∠D = 66°

By property : opposite sides of equal angles are equal

Thus CB=CD

Thus all four sides of quadrilateral ABCD are equal

And diagonal BD bisects the angles

So, it is a rhombus

Thus Option c is correct .

c. Parallelogram ABCD is a rhombus, because the diagonal bisects two angles.

Answer 2

We can analyze the four optons. 1) Option A. A parallelogram with all four angles of the same measure can be either a square or a rectangle, then this option is not valid. 2) Optrion B. gives not information. 3) A rhombus (a diamond) is a parallelogram with four congruent side (square is a specific case of rhmbus but not all rhombus are squares), and it is enouh to say that one diagonal bisects two interior angles, to conclude that it is a rhombus. 4) If a diagonal creates congruent angles, but you do not know what happens with the opposed angle, you cannot conclude that the parallelogram is a rectangle; it could be a trapezoid with one side perpendicular to the parallel sides. By t his analysis, the answer is option C.