A triangle has corners at (3, 8 )(3,8), ( 2, 1 )(2,1), and ( 9 , 6 )(9,6). If the triangle is dilated by 3 x3x around (1, 2)(1,2), what will the new coordinates of its corners be?
1 Answer
Oct 28, 2017
Explanation:
"let the 3 corners be"let the 3 corners be
A=(3,8),B=(2,1)" and "C=(9,6)A=(3,8),B=(2,1) and C=(9,6)
"and "A',B',C'"be the images of "A,B" and "C
"let "D=(1,2)" be the centre of dilatation"
•color(white)(x)A=(3,8)
vec(DA')=3vec(DA)
vec(DA)=ula-uld=((3),(8))-((1),(2))=((2),(6))
rArrvec(DA')=3((2),(6))=((6),(18))
rArrA'=(1+6,2+18)=(7,20)
•color(white)(x)B=(2,1)
vec(DB')=3vec(DB)
vec(DB)=ulb-uld=((2),(1))-((1),(2))=((1),(-1))
rArrvec(DB')=3((1),(-1))=((3),(-3))
rArrB'=(1+3,2-3)=(4,-1)
•color(white)(x)C=(9,6)
vec(DC')=3vec(DC)
vec(DC)=ulc-uld=((9),(6))-((1),(2))=((8),(4))
rArrvec(DC')=3((8),(4))=((24),(12))
rArrC'=(1+24,2+12)=(25,14)
