Answer:
1. The length of the base of the rectangle is 18.9 cm.
2. The height of the rectangle is 50.4 cm.
3. The rectangle's area is 952.56 cm².
Explanation:
Given:
The ratio of the base and height of a rectangle is 3 to 8.
And its perimeter is 138.6 cm.
Now, to write and solve an equation to find the length of the base and height.
Let the length of the base be
![3x.](https://img.qammunity.org/2021/formulas/mathematics/middle-school/5iep6orde9e4sustzufmadgjmdnjqnqwbj.png)
And let the length of the height be
![8x.](https://img.qammunity.org/2021/formulas/mathematics/high-school/5eth9zl19zt36562f822151ahyxluenmf7.png)
Perimeter of rectangle = 138.6 cm.
Now, we put equation to get the base and height by putting formula of perimeter:
![Perimeter=2* base+2* height](https://img.qammunity.org/2021/formulas/mathematics/high-school/5aaw9xbfe1a652bl8nwpdttljxh5te0f6d.png)
![138.6=2* 3x+2* 8x](https://img.qammunity.org/2021/formulas/mathematics/high-school/cpa8wps7gjda4y6bna2lxdso3i8fz5n3xh.png)
![138.6=6x+16x\\\\138.6=22x](https://img.qammunity.org/2021/formulas/mathematics/high-school/urj7kjmlfu3wkn4dfo4xttl3bn9ukpmn2c.png)
Dividing both sides by 22 we get:
![6.3=x\\\\x=6.3.](https://img.qammunity.org/2021/formulas/mathematics/high-school/maxmcja3qk996urwd2fxp86bzx7o61segn.png)
Substituting the value of
:
Base =
![3x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/purdz6z19pdiye69ew5foldw00mwxp0822.png)
=
![3* 6.3=18.9\ cm.](https://img.qammunity.org/2021/formulas/mathematics/high-school/b4pkhv20wb6rs06pf3yewdsn7n7koehubn.png)
Height =
![8x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/6tnvm86xosaz7tb7fom8x08eppt0sqgta1.png)
=
![8* 6.3=50.4\ cm.](https://img.qammunity.org/2021/formulas/mathematics/high-school/oeb949fly7hqndic45tm223pc80nqqzq86.png)
Now, to get the area of the rectangle by putting formula:
![Area=base* height\\\\Area=18.9* 50.4\\\\Area=952.56\ cm^2.](https://img.qammunity.org/2021/formulas/mathematics/high-school/8gtvjk4f53h58u6i7m8ssdhygw1c4ulu96.png)
Therefore, 1. the length of the base of the rectangle is 18.9 cm.
2. The height of the rectangle is 50.4 cm.
3. The rectangle's area is 952.56 cm².