Question

which picture shows a figure being cut by a line of symmetry? options: a triangle with a dashed line, a square with a diagonal dashed line, a parallelogram with a dashed line, all of these

Explanation:

Step1: Recall the definition of line of symmetry

A line of symmetry divides a figure into two congruent (identical) parts.

Step2: Analyze the first figure (triangle)

The given triangle is a scalene triangle. A scalene triangle has no lines of symmetry.

Step3: Analyze the second figure (square)

The line shown in the square is a diagonal. A square has 4 lines of symmetry: 2 diagonals and 2 lines joining the mid - points of opposite sides. But when we fold a square along a diagonal, the two parts (triangles) are congruent.

Step4: Analyze the third figure (parallelogram)

A general parallelogram (non - special like rhombus, rectangle etc.) has no lines of symmetry.

Answer:

The second picture (the square with a diagonal as the line) shows a figure being cut by a line of symmetry.