Is it possible to have a relationship where the ratio of the Lengths is equal to the ratio of the Areas, i.e.,
?
Look at the triangles below:
Do Triangles ACD and ABC have in common? Do they share a common height? [Are you able to locate this common height?]
Example 1:
Look at the diagram below: Triangle ABC shares the same height with Triangles ACD (or Triangle ABD).
Find the ratio of BC: CD
=
5 : 3
Find the ratio of Area BCA: Area CDA
=
0.5*5*2 : 0.5*3*2
=
5 : 3 [Do you know how to get this?]

 PAUSE  Still Confused? Look at the video below:



Question 1:
Look at the diagram below:
Find the Area of Triangle ABC: Area of Triangle ACD. [**Questions: Do I need to find the actual areas for the 2 triangles? Do I need to know the perpendicular height for both the triangles?]
Question 2:
Look at the diagram below:
Given that ABCD is a paralleogram and area of triangle CEF : area of triange ADE = 1 : 9 Find the ratio of Area triangle CEF: Area of parallelogram ABCD?
[Answer: 1 : 24 ]  Are you able to derive to this answer?   
Homework (to be submitted in hardcopy) Please download the Worksheet and Assignment.
Areas for nonsimilar figures
Is it possible to have a relationship where the ratio of the Lengths is equal to the ratio of the Areas, i.e.,?
Look at the triangles below:
Do Triangles ACD and ABC have in common? Do they share a common height? [Are you able to locate this common height?]
Example 1:
Look at the diagram below:Triangle ABC shares the same height with Triangles ACD (or Triangle ABD).

PAUSE  Still Confused? Look at the video below:



Question 1:
Look at the diagram below:Find the Area of Triangle ABC: Area of Triangle ACD.
[**Questions: Do I need to find the actual areas for the 2 triangles? Do I need to know the perpendicular height for both the triangles?]
Question 2:
Look at the diagram below:Given that ABCD is a paralleogram and area of triangle CEF : area of triange ADE = 1 : 9
Find the ratio of Area triangle CEF: Area of parallelogram ABCD?
[Answer: 1 : 24 ]  Are you able to derive to this answer?



Please download the Worksheet and Assignment.
For Mr Colin Toh's classes, please use this:
Complete both the work by Week 4, Monday [18 July 2011]