Which of the following must be a square? a. a figure whose diagonals are congruent and meet right angles b. a figure whose diagonals are congruent and meet at right angles c. a figure whose sides are parallel and meet at right angles d. a figure whose sides are congruent

Option (B).

Step-by-step explanation:

A square is a type of quadrilateral in which opposite sides are parallel and equal. All sides of square are equal. The angles of square are equal and each angle is 90°.

Diagonals of square are equal and bisect each other at right angles. Hence, the diagonals are congruent and bisect each other at right angles,

Therefore option (B) is correct.

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.