Construction of a kite
Let us learn how to construct a kite when two diagonals are provided.
Example:
Construct a kite \(ABCD\) with diagonals \(AC = 10 \ cm\) and \(BD = 8 \ cm\).
 
Rough figure:
 
42.png
 
For kite \(ABCD\), diagonal \(AC\) bisects the diagonal \(BD\).
 
Thus, \(OB = OD = \frac{8}{2} = 4 \ cm\)
 
Also, the diagonals are perpendicular to each other.
 
\(\angle AOB = \angle BOC = \angle COD = \angle DOA = 90^{\circ}\)
 
Construction:
 
Step 1: Draw a line segment \(AC = 10 \ cm\).
 
43.png
 
Step 2: Mark a point \(O\) anywhere on the line segment \(AC\) and draw a perpendicular line to \(AC\) passing through \(O\).
 
44.png
 
Step 3: With \(O\) as the centre and \(4 \ cm\) as the radius, draw two arcs on the perpendicular line that intersect at \(B\) and \(D\).
 
45.png
 
Step 4: Join \(AB\), \(BC\), \(CD\) and \(DA\).
 
46.png
 
Thus, \(ABCD\) is the required kite.
Construction of an isosceles trapezium
Let us learn how to construct an isosceles trapezium in which the non-parallel sides are equal in length.
Construct an isosceles trapezium \(ABCD\) with \(AB \parallel CD\) and \(AB = 7 \ cm\) and \(AD = BC = 5 \ cm\).
 
Rough diagram:
 
47.png
 
Construction:
 
Step 1: Draw a line segment \(AB = 7 \ cm\).
 
48.png
 
Step 2: Draw a horizontal line parallel to \(AB\).
 
49.png
 
Step 3: With \(A\) and \(B\) as centres and a radius of \(5 \ cm\), draw an arc that cuts the horizontal line at \(D\) and \(C\), respectively.
 
50.png
 
Step 4: Join \(AD\) and \(BC\).
 
51.png
 
Thus, \(ABCD\) is the required isosceles trapezium.