84/120 can be reduced to 7/10
42/6 but if you want to simplify, it's 7
5.7 of anything minus 3.9 of the same thing leaves 1.8 of them.
Ratio of areas of similar triangles is 9 : 25.
Solution:
Given data:
Ratio of sides of two similar triangles = 3 : 5
To find the ratio of areas of the triangles:
We know that,
<em>In two triangles are similar, then the ratio of their area is equal to the square of the ratio of their sides.</em>



Ratio of areas of similar triangles is 9 : 25.