A triangle has coordinates A (1, 5), B (-2, 1) and C (0, -4). What are the new coordinates if the triangle is rotated 90° clockwise around the origin?

Question

anonymous · Answer

@ganeshie8

ganeshie8 · Answer

90 degree clockwise 

is same as

270 degree counter clockwise

ganeshie8 · Answer

remember the rule for 270 degree counter clockwise rotation ?

anonymous · Answer

(A,B) (B,-A)

ganeshie8 · Answer

Yes! 270 degree counter clockwise rule is
$$(A,~~B)\longrightarrow  (B, ~-A)$$

ganeshie8 · Answer

apply it on each of the given coordinates

ganeshie8 · Answer

$$(1,~~5)\longrightarrow  ?$$

anonymous · Answer

A(1,5) --> (1,-5)
B(-2,1) --> (-2,-1)
C(0,-4) --> (0,4)

ganeshie8 · Answer

not quite
you need to swap x and y coordinates

ganeshie8 · Answer

$$(1,~~5)\longrightarrow  (5,~-1)$$

ganeshie8 · Answer

see if you can work remaining two vertices

anonymous · Answer

ohh sorry i forgot..
B(-2,1) -->(1,2)

ganeshie8 · Answer

Yes!

anonymous · Answer

C(0,-4) --> (-4,-0)

ganeshie8 · Answer

Excellent!  -0 is same as 0 so
$$(0,~-4)\longrightarrow (-4,~0)$$

anonymous · Answer

ok so is that all i have to do?

ganeshie8 · Answer

yes we're done!

anonymous · Answer

ok thanks alot! :D