- #1
pavadrin
- 156
- 0
Hey,
this proof has been annoying me all day. i don't understand what its asking do and have no idea how to solve it. The proof asks:
Prove that the altitudes of a traingle are concurrent.
Here is the diagram for it:
http://img246.imageshack.us/img246/1899/pfji4.jpg
[tex]
\begin{array}{l}
\overrightarrow {FA} = {\bf{a}} \\
\overrightarrow {FC} = {\bf{c}} \\
\overrightarrow {FB} = {\bf{b}} \\
\end{array}
[/tex]
Im also told to use the fact that
[tex]{\bf{a}} \cdot \overrightarrow {BC} = 0[/tex]
and
[tex]{\bf{b}} \cdot \overrightarrow {AC} = 0[/tex]
to prove that [tex]\overrightarrow {CF}[/tex] is perpendicualr to [tex]\overrightarrow {AB}[/tex]
thanks to anyone who understands what this is asking me to do and post back helpful infomation,
Pavadrin
this proof has been annoying me all day. i don't understand what its asking do and have no idea how to solve it. The proof asks:
Prove that the altitudes of a traingle are concurrent.
Here is the diagram for it:
http://img246.imageshack.us/img246/1899/pfji4.jpg
[tex]
\begin{array}{l}
\overrightarrow {FA} = {\bf{a}} \\
\overrightarrow {FC} = {\bf{c}} \\
\overrightarrow {FB} = {\bf{b}} \\
\end{array}
[/tex]
Im also told to use the fact that
[tex]{\bf{a}} \cdot \overrightarrow {BC} = 0[/tex]
and
[tex]{\bf{b}} \cdot \overrightarrow {AC} = 0[/tex]
to prove that [tex]\overrightarrow {CF}[/tex] is perpendicualr to [tex]\overrightarrow {AB}[/tex]
thanks to anyone who understands what this is asking me to do and post back helpful infomation,
Pavadrin
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