Question 19
Construct the following figures:


Geometric constructions can be performed using a straightedge (ruler) and a compass:
- Compass: Used to draw circles and arcs of a fixed radius, or transfer equal lengths.
- Straightedge: Used to draw straight lines between points.
- For figures with 6-fold rotational symmetry (like hexagons, 6-petal flowers, and 7-circle arrangements), the fundamental principle is that the side length of a regular hexagon inscribed in a circle is equal to the radius of the circle.
(a) Construct Figure (a): Inflexed Arc
Step 1 · Construct an Inflexed Arc

- Draw a horizontal base line segment .
- Draw vertical lines upwards from and . Mark points on the vertical line at and on the vertical line at such that .
- Find the midpoint of segment .
- Draw a vertical centerline upwards through .
- Set the compass radius to .
- Place the compass at center and draw an arc curving towards the centerline.
- With the same radius (), place the compass at center and draw an arc curving towards the centerline.
- The two arcs intersect at point on the vertical centerline, completing the figure formed by vertical segments , and arcs , .
(a) Figure (a) constructed.
(b) Construct Figure (b): Flower-like Shape
Step 1 · Construct a Flower-like Shape

- Draw a central circle with center and radius .
- Mark any point on the circumference of the central circle.
- With center and radius , draw a circle passing through and intersecting the central circle at two points; label one point .
- With center and radius , draw another circle intersecting the central circle at a new point .
- Repeat this process around the circumference using each new intersection point as the center until 6 surrounding circles are drawn.
- The overlapping arcs inside the central circle form the 6 petals.
(b) Figure (b) constructed.
(c) Construct Figure (c): Hexagon inside a Circle
Step 1 · Construct a Regular Hexagon Inscribed in a Circle

- Draw a circle with center and radius .
- Mark a point on the circumference.
- With center and compass set to radius , draw an arc to cut the circle at point .
- With center and radius , draw an arc to cut the circle at point .
- Continue marking points around the circumference with radius until 6 points () are marked.
- Connect consecutive vertices with straight lines () to form the regular hexagon.
(c) Figure (c) constructed.
(d) Construct Figure (d): Seven Circles
Step 1 · Construct Seven Intersecting Circles

- Draw a central circle with center and radius .
- Choose a point on the circumference and draw a circle of radius centered at .
- Locate the intersection point of this circle with the central circle.
- Draw the next circle of radius centered at .
- Continue moving to each successive intersection on the central circle until all 6 surrounding circles are drawn.
- Keep all 7 full circles visible to complete the design.
(d) Figure (d) constructed.
(e) Construct Figure (e): Tiling Pattern
Step 1 · Construct a Hexagonal Tiling Pattern

- Draw a circle with center and radius , and construct an inscribed regular hexagon with vertices .
- Draw segments from center to each vertex , dividing the hexagon into 6 large equilateral triangles (e.g., ).
- In each equilateral triangle:
- Divide each side () into 3 equal segments.
- Connect corresponding division points with lines parallel to the sides of the triangle, subdividing each large triangle into 9 smaller equilateral triangles.
- Repeat for all 6 large equilateral triangles to reveal the complete geometric tiling pattern of stars and smaller hexagons.
(e) Figure (e) constructed.
- Changing Compass Radius: Changing the compass opening during the step-by-step construction of hexagonal or circle patterns will prevent the arcs from closing properly back at the starting point.
- Imprecise Midpoint / Division: In tiling patterns, dividing triangle edges unequally will cause the internal grid lines not to align parallel to the outer edges.
More questions in FIO
When constructing the perpendicular bisector, is it necessary to have the same radius for the arcs above and below ? Explore this through construction, and then justify your answer.
[Hint 1: Any point that is of the same distance from and lies on the perpendicular bisector.
Hint 2: We can draw the whole line if any two of its points are known.]
Is it necessary to construct the pairs of arcs above and below ? Instead, can we construct both the pairs of arcs on the same side of ? Explore this through construction, and then justify your answer.
While constructing one pair of intersecting arcs, is it necessary that we use the same radii for both of them ? Explore this through construction, and then justify your answer.
Recreate this design using only a ruler and compass —
Justify why in Fig. 6.4 is the perpendicular bisector.
Can you think of different methods to construct a angle at a given point on a line using a rope?
Construct at least 4 different angles. Draw their bisectors.
Construct the 8-petalled figure shown in Fig. 6.5.
In Step 2 of angle bisection, if arcs of equal radius are drawn on the other side, as shown in the figure, will the line still be an angle bisector? Explore this through construction, and then justify your answer.
What are the other angles that can be constructed using angle bisection? Can you construct angle?
Come up with a method to construct the angle bisector using a rope.
Construct the following figure.
How do we construct the petals so that they are of the maximum possible size within a given square?
Construct at least 4 different angles in different orientations without taking any measurement. Make a copy of all these angles.
Construct the Fig. 6.6.
Construct 4 pairs of parallel lines in different orientations.
Construct the following figure.
Use support lines in Fig. 6.11 to construct a pointed arch. Make different arches, by changing the radius of the arcs.
Make your own arch designs.
Construct the following figures:
Optical Illusion: Do you notice anything interesting about the following figure? How does this happen? Recreate this in your notebook.
Construct this figure.
[Hint: Find the angles in this figure.]
Draw a line and mark a point anywhere outside the line. Construct a perpendicular to the given line through .
[Hint: Find a line segment on whose perpendicular bisector passes through .]
How can the tangram pieces be rearranged to form each of the following figures?
Are the following tilings possible?