Question Video: The Right-Angled Triangle Altitude Theorem | Nagwa Question Video: The Right-Angled Triangle Altitude Theorem | Nagwa

# Question Video: The Right-Angled Triangle Altitude Theorem Mathematics • Second Year of Preparatory School

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What is (π΄π·)Β² equal to?

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### Video Transcript

What is π΄π· squared equal to?

Some of you when you look at this triangle might immediately start thinking about algebra and substitution. And if you try to do this that way, youβre going to spiral down into a very long trail of substitution. There is a more simple way to approach this.

Weβre going to set up a proportion. Hereβs triangle π΄π΅π· and triangle π΄π·πΆ. Proportionally, π΅π· over π΄π· would be equal to π΄π· over πΆπ·. Once we have this proportion β π΅π· over π΄π· is equal to π΄π· over πΆπ· β we can cross-multiply. π΄π· times π΄π· is equal to π΅π· times πΆπ·. π΄π· times π΄π· is equal to π΄π· squared, which is equal to π΅π· times πΆπ·.

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