Mathematics
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OpenStudy (anonymous):
The coordinates J(2, 2), K(-1, 3), L(-2, -1) form a right triangle. true or false
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OpenStudy (anonymous):
@jim_thompson5910
OpenStudy (anonymous):
Plot the points. Then use the distance formula. If the Pythagorean theorem holds, then it's a right triangle.
OpenStudy (anonymous):
i dont have anything to plot them on
OpenStudy (anonymous):
\[d=\sqrt{\Delta x ^{2}+\Delta y ^{2}}\]
jimthompson5910 (jim_thompson5910):
you need to use the distance formula to find the segments
JK
KL
JL
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jimthompson5910 (jim_thompson5910):
if you can show that
a^2 + b^2 = c^2
is true, where a,b,c are the 3 side lengths and c is the longest side, then the triangle is a right triangle
OpenStudy (anonymous):
|dw:1366688771729:dw|
OpenStudy (anonymous):
so its kinda long process to find im guessing okayyyyyyy here we go
jimthompson5910 (jim_thompson5910):
yes it's quite long since you need to use the formula hairynmad gave you to find JK, KL and JL
jimthompson5910 (jim_thompson5910):
once you have those 3 sides, you plug them into a^2 + b^2 = c^2 to test if it's a right triangle or not
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OpenStudy (anonymous):
can you help e set up the first one just to make sure im doing it right
jimthompson5910 (jim_thompson5910):
which side length do you want to find
JK
KL
JL
??
OpenStudy (anonymous):
jk
OpenStudy (anonymous):
is the answer to it sqrt10
OpenStudy (anonymous):
?
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OpenStudy (anonymous):
yes
OpenStudy (anonymous):
okay so after i get all those answers how do i plug them into the a2+b2=c2?
OpenStudy (anonymous):
like does it matter where i place them in the equation?
OpenStudy (dwelsher):
false
OpenStudy (anonymous):
longest side will be c, the hypotenuse
the other two, the legs, don't matter, can be either a or b
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jimthompson5910 (jim_thompson5910):
as long as c is the longest side, everything else doesn't matter
OpenStudy (anonymous):
okay gotcha . so is it sqrt10 or no?
jimthompson5910 (jim_thompson5910):
correct, JK = sqrt(10)
OpenStudy (anonymous):
okay
OpenStudy (anonymous):
sooooo this is what i got
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OpenStudy (anonymous):
sqrt10^2+ sqrt17 ^2 = sqrt25^2
OpenStudy (anonymous):
hwo the heck do i work that out
jimthompson5910 (jim_thompson5910):
one sec while I check
OpenStudy (anonymous):
i got false it is not a right triangle am i right?
OpenStudy (anonymous):
okay
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jimthompson5910 (jim_thompson5910):
KL = sqrt(17)
that's correct
jimthompson5910 (jim_thompson5910):
JL = sqrt(25) which is really just 5
so
JL = 5
jimthompson5910 (jim_thompson5910):
a^2 + b^2 = c^2
(JK)^2 + (KL)^2 = (JL)^2
(sqrt(10))^2 + (sqrt(17))^2 = (5)^2
10 + 17 = 25
27 = 25
This is FALSE, so a^2 + b^2 = c^2 is FALSE when
a = sqrt(10)
b = sqrt(17)
c = 5
jimthompson5910 (jim_thompson5910):
so yes, you're correct
this isn't a right triangle
OpenStudy (anonymous):
okay wow that really helps i appreciate the help both of you so much
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jimthompson5910 (jim_thompson5910):
you're welcome