Suppose triangle ABC ~ triangle GHI with scale factor 3:5, and AB=9, BC=18 and AC=21. What is the perimeter of triangle GHI?

1 Answer
Dec 15, 2015

color(white)(xxxx)80

Explanation:

color(white)(xx)|AB|/|GH|=3/5
=>color(red)9/|GH|=3/5
=>|GH|=15

color(white)(xx)|BC|/|HI|=3/5
=>color(red)18/|HI|=3/5
=>|HI|=30

color(white)(xx)|AC|/|GI|=3/5
=>color(red)21/|GI|=3/5
=>|GI|=35

Therefore perimeter is:
color(white)(xx)|GH|+|HI|+|GI|=15+30+35
color(white)(xxxxxxxxxxxxxxx)=80