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A triangle is a closed figure bounded by three line segments.

The area of a closed plane figure is the measure of the region (surface) by its boundary.

Area of Triangle = $\frac{1}{2}  ·  \text{base}  ·  \text{height}$square unit

Suppose a, b, and c is three real numbers.

Distributive Property of Multiplication

Property: $\text{a}  (  \text{b}  -  \text{c}  )    =  \text{a}  ·  \text{b}  -  \text{a}  ·  \text{c}$

Example: $\text{12}  \text{(6}  \text{-}  \text{4}  \text{)}  =  \text{12}  ·  \text{6}  -  \text{12}  ·  \text{4}  =  72  -  48  =  24$

In this figure the base is 6 – 2y and height = 13

We know that area of Triangle =$\frac{1}{2}  ·  \text{base}  ·  \text{height}$

Find the area, using the distributive method of multiplication.

Property: $\text{a}  (  \text{b}  -  \text{c}  )    =  \text{a}  ·  \text{b}  -  \text{a}  ·  \text{c}$

Area =$\frac{1}{2}  ·  \text{( 6}-\text{2y)}  ·  \text{13}  =  (3  -  y)  ·  13\text{= 3}  ·  \text{13}  -  y  ·  13  =  39  -  13y$square units

Area of the Triangle is 39 – 13y sq unit.