1. Area of a Kite and a Rhombus
Calculate the area of quadrilaterals. Quadrilaterals include squares, rectangles, rhombuses, parallelograms, trapezoids and kites. When formulas are used, be able to explain why they are valid.

2. I can… Determine the area of a rhombus and a kite Self Assessment
5- I can do it without help & teach others.
4- I can do this with no help, but I don’t know if I can explain it.
3- I can do this with a little help.
2- I can do this with a lot of help!
1- I don’t have a clue.

3. Kite and Rhombus
The formula for the area of a rhombus can be justified using the area of a triangle. A specific case follows.
The diagonals divide a rhombus and kite into 4 congruent right triangles. So, the area of the rhombus or a kite is 4 times the area of one of the right triangles.
Area of 1 triangle = 1/2bh = ½(3)(4) = 6
Area of 4 triangles = 4(6) = 24
Notice that 1/2d1d2 or ½(6)(8), also equals 24

4. Area of a RHOMBUS or a KITE
Only one formula to know! It’s the same for both!
Area = ½ the product of the lengths of the diagonals
Area = or
PLEASE, PLEASE, PLEASE BE CAREFUL!!! IT IS THE PRODUCT OF THE DIAGONALS, NOT THE SUM!!

5. Find the area of the kite.
A = d1d2 B C D A
DB = 10m
AC = 17m
Find the area of the kite.
A kite = ½ (10)(17)
= 85m2

6. Find the Area of a Kite A = d1d2 A kite = ½ (7)(6) = 21units2
AB = = 7
CD = = 6 2 3 3
A = d1d2 5
A kite = ½ (7)(6)
= 21units2

7. Find the Area of a Rhombus
= 24
= 24
A = d1d2
12 m
A rhombus = ½ (24)(24)
= 288m2

8. Your Turn… A = d1d2 A kite = ½ (12)(9) = 54units2 AB = 4.5 + 4.5 = 9
CD = = 12
4.5 2 10
A = d1d2
A kite = ½ (12)(9)
= 54units2

9. Your Turn… A = d1d2 A rhombus = ½ (24)(52) = 624 units2 12 + 12 = 24
= 52
A = d1d2
A rhombus = ½ (24)(52)
= 624 units2

10. I can… Determine the area of a rhombus and a kite Self Assessment
5- I can do it without help & teach others.
4- I can do this with no help, but I don’t know if I can explain it.
3- I can do this with a little help.
2- I can do this with a lot of help!
1- I don’t have a clue.

11. A = ½ d1•d2 Area of a Rhombus and a Kite 10.2 Notes
Determine the length of the diagonals
Copy the equation (don’t just solve in your head)
Substitute the numbers for the variables
Solve