What's the length of the |AC| ?

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2 Answers
Sep 17, 2017

#AC=5sqrt2#

Explanation:

If #AB ⊥ BC#, and #AB=5#, then #BC=5#. This is a right angled triangle, which means sides#a^2+b^2=c^2#. In this case #a=AB=5,# #b=BC=5,# and #c=AC#. Therefor
#5^2+5^2=(AC)^2#
#25+25=(AC)^2#
#50=(AC)^2#
#sqrt50=AC#

From here we can simplify #sqrt50#, since
#sqrt50=sqrt(5*5*2)=5sqrt2#

I hope I helped!

Sep 17, 2017

#AC=8 1/3cm.#

Explanation:

As #BH=3# and #AB=5#, as #Delta ABH# is right angled at #H#, using Pythagoras Theorem

#AH=sqrt(5^2-3^2)=sqrt(25-9)=sqrt16=4#

In a right angled triangle, right angled at #/_B#, if we connect midpoint of hypotenuse to #B#, then

#BD=AD=DC#.

Ler this be #x# and then #HD=x-3# and using Pythagoras Theorem on #DeltaAHD#, we have

#AH^2+HD^2=AD^2# or #4^2+(x-3)^2=x^2#

i.e. #x^2-6x+9+16=x^2#

or #6x=25# and #x=25/6=4 1/6#

Hence, #AC=25/6xx2=25/3=8 1/3cm.#