Question

rectangle below about the marked point?
choose all answers that apply.
90°
180°
270°
none of the above

Explanation:

Step1: Recall rotational symmetry of rectangle

A rectangle has rotational symmetry of order 2. The angles of rotation for rotational symmetry are \(n\times180^{\circ}\), where \(n = 1,2,\cdots\).

Step2: Check each option

• For \(90^{\circ}\): A rectangle rotated by \(90^{\circ}\) about its center (the marked point) does not map onto itself.
• For \(180^{\circ}\): A rectangle rotated by \(180^{\circ}\) about its center maps onto itself.
• For \(270^{\circ}\): \(270^{\circ}=360^{\circ}- 90^{\circ}\), and a rectangle rotated by \(270^{\circ}\) about its center does not map onto itself.

Answer:

B. \(180^{\circ}\)