## What are we learning ?

**Competency in Focus:** 2D Geometry (Area of Rectangle)

This problem from American Mathematics contest (AMC 8, 2019) is based on calculation of area of **Rectangle** .

## First look at the knowledge graph

## Next understand the problem

Three identical rectangles are put together to form rectangle $ABCD$, as shown in the figure below. Given that the length of the shorter side of each of the smaller rectangles is 5 feet, what is the area in square feet of rectangle $ABCD$?

##### Source of the problem

American Mathematical Contest 2019, AMC 8 Problem 2

##### Key Competency

### 2D Geometry (Area of Rectangle)

##### Difficulty Level

3/10

##### Suggested Book

Challenges and Thrills in Pre College Mathematics

## Start with hints

Do you really need a hint? Try it first!

The length of the smaller side of each rectangle is given 5 feet. So using the diagram we can find that the larger side of the small rectangle is 2 times the length of the smaller side.

So find the longer side which is 5*2 = 10 feet.

the area of the identical rectangles is 5*10 = 50 square feet

Thus at end we have 3 identical rectangles formed a bigger rectangle……Try to solve … 50*3 = 150 square feet

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