Answer: I don’t know if you want the area or just y but anyways, y= 9
Explanation:
The question requires a scale factor (since both triangles have similar sides (an equal ratio is a good way to think about it) the 10cm side of the large triangle is proportionate to the same side of the smaller triangle.
In other words to get that scale factor (how much one shape is bigger than the other) we need to divide the 10 by 4 (you need to use the same side you can’t do 10/6 because they are completely different sides) 10/4 = 2.5
Now we know the larger triangle is 2.5 times bigger than the smaller triangle. This means the smaller triangle is 2.5 times smaller than the big triangle. So to find the base of the larger triangle we use a similar method we used to find the scale factor (but not divide multiply because when you want to find the bigger you multiply when you want to find scale factor/ smaller you divide) so 6* 2.5= 15 and since y is not the entire base only a part of it, we can do 15(which is the entire length of the big triangle base) - 6 = 9
Therefore y=9