Answer:
14.422 feet
Explanation:
The campers decided to build a fly, or rain cover, over their tent.
The fly will be 12 feet high and 16 feet wide.
Refer the attached figure
AD =12 feet
BC = 16 feet
The fly is in the shape of cone we take cut section of it in the form of triangle.
So, the triangle is isosceles triangle .
Since AD is the perpendicular bisector of the isosceles triangle .So, BD = DC
So, D is the midpoint of BC
So, BD= DC=
![(BC)/(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/nmk9gxbo75o20suihjnf4j89nulny79nwe.png)
BD= DC=
![(16)/(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/gfieoq1wsfnu3zdf09uf8q0qmdve89c38w.png)
BD= DC= 8
So, we will use Pythagoras theorem in ΔADC
![Hypotenuse^2=Perpendicular^2+Base^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/c7xgv714d2awbmjndnu2sdu2u86knvc80u.png)
![AC^2=AD^2+DC^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/go00cm200vkwqreo4tydmil76v2mcexdce.png)
![AC^2=12^2+8^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/oi3o18v5smx4xdjzifsnlnfz7pj17y8wmf.png)
![AC^2=144+64](https://img.qammunity.org/2019/formulas/mathematics/middle-school/yref6n8p7m8wgk00h96tahb45y69eknk6e.png)
![AC^2=208](https://img.qammunity.org/2019/formulas/mathematics/middle-school/5904ipdqrsovyrbx0q8m7c7na4u2ak62vu.png)
![AC=√(208)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/gu1mcdfuregt9iq8uezjqy9s6754u4109z.png)
![AC=14.422](https://img.qammunity.org/2019/formulas/mathematics/middle-school/d8qu79vtjekj6xxhjfo8ywj1pxkxsb50ym.png)
The minimum length of the slanted piles needed to support the fly is 14.422 feet.