Geometry finding the measure of a kite

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rachelmaddie

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I need help with solving the rest of this.
Since DOC is a right triangle
First use Pythagorean theorem to find the measure of DO.
DC^2 = DO^2 + OC^2
Substitute
7^2 = DO^2 + 5^2
DO^2 = 7^2 - 5^2
DO^2 = 49 - 25
DO^2 = 24
DO = rt24

67E4D4A7-4E41-40B6-AAE4-23184C1849E1.png
 
rachelmaddie said:
I need help with solving the rest of this.
Since DOC is a right triangle
First use Pythagorean theorem to find the measure of DO.
DC^2 = DO^2 + OC^2
Substitute
7^2 = DO^2 + 5^2
DO^2 = 7^2 - 5^2
DO^2 = 49 - 25
DO^2 = 24
DO = rt24

View attachment 14378
Click to expand...
There are few similar triangles here. What are those?
 
One approach is to set up an equation using 2 expressions for the area of COD. Another - similar triangles (but not the ones you found).
 
Break up the base that is 7. Part of it is in one triangle and part of it is in another triangle.
 
OD = √(7^2-5^2) = √24

To find area of ODC
(1/2)(OC × OD) = (1/2)(CD×OP)

5×√24 = x × 7
x = 10√6/7
 
rachelmaddie said:
How do I justify this?
Click to expand...
Seems obvious to me. E.g. where did (1/2)(OC × OD) come from? There is a reason for each step in a solution. If you don't know the reason, why did you write down the step? If you know the reason - that's your justification.
 
lev888 said:
Seems obvious to me. E.g. where did (1/2)(OC × OD) come from? There is a reason for each step in a solution. If you don't know the reason, why did you write down the step? If you know the reason - that's your justification.
Click to expand...
If you know the length of the diagonals of a kite, you can find the area.
 
rachelmaddie said:
If you know the length of the diagonals of a kite, you can find the area.
Click to expand...
Is this supposed to cover everything? It's too general. Justification applies to specific steps. E.g. this follows from the Pythagorean theorem, this - from right triangle area formula, etc.
 
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