# Ratio and Proportion

Philosophy of Mathematics |

While creating a resource page, please click here for a resource creation **checklist**.

# Concept Map

# Textbook

To add textbook links, please follow these instructions to: (Click to create the subpage)

# Additional Information

## Useful websites

## Reference Books

1. Cabinet of mathematical curiosities - Ian Stewart

2. Cabinet of mathematical curiosities - Ian Stewart

# Teaching Outlines

## Concept #

### Learning objectives

### Notes for teachers

For Solved Problems Click [1]

[here]

### Activity No #

**Estimated Time****Materials/ Resources needed****Prerequisites/Instructions, if any****Multimedia resources****Website interactives/ links/ Geogebra Applets****Process (How to do the activity)****Developmental Questions (What discussion questions)****Evaluation (Questions for assessment of the child)****Question Corner**

**How to make text bold***How to make text italic*

### Activity No #

**Estimated Time****Materials/ Resources needed****Prerequisites/Instructions, if any****Multimedia resources****Website interactives/ links/ Geogebra Applets****Process (How to do the activity)****Developmental Questions (What discussion questions)****Evaluation (Questions for assessment of the child)****Question Corner**

## Concept #

### Learning objectives

### Notes for teachers

*These are short notes that the teacher wants to share about the concept, any locally relevant information, specific instructions on what kind of methodology used and common misconceptions/mistakes.*

### Activity No #

**Estimated Time****Materials/ Resources needed****Prerequisites/Instructions, if any****Multimedia resources****Website interactives/ links/ Geogebra Applets****Process (How to do the activity)****Developmental Questions (What discussion questions)****Evaluation (Questions for assessment of the child)****Question Corner**

### Activity No #

**Estimated Time****Materials/ Resources needed****Prerequisites/Instructions, if any****Multimedia resources****Website interactives/ links/ Geogebra Applets****Process (How to do the activity)****Developmental Questions (What discussion questions)****Evaluation (Questions for assessment of the child)****Question Corner**

# Hints for difficult problems

# =Ratio and Proportionality

### Exercise 2.4.2

In the adjacent figure, two triangles are similar. Find the length of the missing side This problem can be solved with the following steps.

- Prerequisites: students should know the concept of similarity and proportionality

*Proportionality : two ratios are equal then four quantities are in proportional

*Similar Triangles : If two triangles are said to be similar 1. if they are equiangular 2. the corresponding side are proportional

- Understanding/ analysing the given problem
- Identifying/ Naming the triangles
- Identifying the sides whose length is not given
- comparing two sides of triangles (visualising that 1st triangle is smaller than 2 nd triagle and viceversa
- should identify the corresponding sides (sides having same allignment)

- Procedure
- find the ratio between the corresponding sides whose length is known
- express proportional corresponding sides (using the property of similarity)

AC/DF = AB/DE

13/39 = 5/x 13 : 39 = 5 : x (use the property of proportionality i.e Product of extremes is equal to product of means) 13 * x = 39 * 5

x = 39* 5 /13

Use the following Geogebra applet to understand proportion

# Project Ideas

# Math Fun

**Usage**

Create a new page and type {{subst:Math-Content}} to use this template