Which transformation will always map a parallelogram onto itself? a. a 90° rotation about its center b. a reflection across one of its diagonals c. a 180° rotation about its center d. a reflection across a line joining the midpoints of opposite sides

The correct answer option is C. a 180° rotation about its center.

Step-by-step explanation:

We are to determine whether which of the transformations will always map a parallelogram onto itself.

We know that a parallelogram has a rotational symmetry of 2 so during a rotaion of 360 degrees, a parallelogram maps onto itself twice, which is at 180^{\circ} and 360^{\circ} about its center.

Therefore, the correct answer option is C. a 180° rotation about its center.

15

step-by-step explanation:

we are given the following expression and we are to solve it and find the product:

-13 × (-5)

solving the given expression in the standard order of solving a mathematical expression, beginning with the opening of brackets and then multiplying the terms and changing their signs.

-3 × -5 = 15 (answer is positive because when negative is multiplied with negative, it gives a positive answer)