Solved examples: Completing symmetrical figures (Grade 4)

📚 Quick Study Guide

• 📐 Definition of Symmetry: A figure is symmetrical if it can be folded along a line (the line of symmetry) so that the two halves match perfectly.
• зеркало Mirror Images: Symmetrical figures create mirror images across the line of symmetry. Imagine a mirror placed on the line; each half reflects the other.
• ✍️ Completing Symmetrical Figures: To complete a symmetrical figure, you need to draw the mirror image of the existing part on the other side of the line of symmetry.
• 📏 Distance and Angles: When drawing the mirror image, maintain equal distances from the line of symmetry and the same angles.
• 💡 Tips for Accuracy: Use a ruler to ensure accurate distances, and carefully observe the angles to create an accurate reflection. Start with key points and then connect them.

Practice Quiz

1. Which of the following figures is symmetrical?
   1. A) A scalene triangle
   2. B) A rectangle
   3. C) A parallelogram
   4. D) A trapezoid
2. Which of the following lines is a line of symmetry for a square?
   1. A) A diagonal
   2. B) A line from one vertex to the midpoint of the opposite side
   3. C) A line parallel to one side but not passing through the center
   4. D) Any line
3. If a symmetrical figure has a point 3 cm to the left of the line of symmetry, where will the corresponding point be located?
   1. A) 3 cm to the right
   2. B) 6 cm to the left
   3. C) 3 cm to the left
   4. D) On the line of symmetry
4. Which of the following shapes can NOT be completed to form a symmetrical shape?
   1. A) A semicircle
   2. B) A quarter circle
   3. C) A straight line segment
   4. D) Any shape can be completed
5. In a symmetrical figure, if an angle on one side of the line of symmetry is 60 degrees, what will the corresponding angle be on the other side?
   1. A) 60 degrees
   2. B) 30 degrees
   3. C) 120 degrees
   4. D) 90 degrees
6. Which of the following words has a vertical line of symmetry when written in capital letters using a symmetrical font?
   1. A) MATH
   2. B) LOOK
   3. C) TIME
   4. D) DATE
7. What is the minimum number of lines of symmetry a regular pentagon has?
   1. A) 5
   2. B) 1
   3. C) 0
   4. D) 2