A triangle has corners at $(5, 8 )$ , $( 3, 1 )$ , and $( 9 , 2 )$ . If the triangle is dilated by $3 x$ around $(4, 2)$ , what will the new coordinates of its corners be?

Question

2116 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-02-20T08:22:33

New coordinates are

$A’ ((7),(20)), B’ ((1),(-1)), C’ ((19),(2))$

$A (5,8), B(3,1), C(9,2)$

Dilated around D(4,2) by a factor of 3.

$vec(AD) = 3 * vec(AB)$

$A’ = 3A - 2D = 3((5),(8)) - 2((4),(2)) = ((15),(24)) - ((8),(4)) = ((7),(20))$

$B’ = 3B - 2D = 3((3),(1)) - 2((4),(2)) = ((9),(3)) - ((8),(4)) = ((1),(-1))$

$C’ = 3C - 2D = 3((9),(2)) - 2((4),(2)) = ((27),(6)) - ((8),(4)) = ((19),(2))$

A triangle has corners at (5, 8 )(5, 8 ), ( 3, 1 )( 3, 1 ), and ( 9 , 2 )( 9 , 2 ). If the triangle is dilated by 3 x 3 x around (4, 2)(4, 2), what will the new coordinates of its corners be?