The student can develop and use formulas to find the areas of rhombi and kites. Rhombi and kites can each be split into two congruent triangles using their diagonals. The area of each triangle is half the product of the diagonals, and the total area is the sum of the two triangular areas. For example, if a kite has one diagonal of 12 inches and an area of 96 square inches, the other diagonal can be calculated as 16 inches.

1. Rhombi & Kites
The student is able to (I can):
• Develop and use formulas for finding the areas of rhombi
and kites

2. Rhombi,
squares, and
kites
A rhombus or kite can be split into two
congruent triangles along its diagonals
(since the diagonals are perpendicular):
Area of one triangle =
Two triangles =
(Squares can use the same formula.)
( )  = 
 
1 2 1 2
1 1 1
d d d d
2 2 4
  = 
 
1 2 1 2
1 1
2 d d d d
4 2

3. Example Find the d2 of a kite in which d1 = 12 in. and
the area = 96 in2.
= 1 2d d
A
2
= 212d
96
2
=26d 96
=2d 16 in.