The value of the side x is 10
To determine the value of the variable x , we need to know the scale factor of the triangles.
Now, we know that scale factor is a multiplier that shows how much larger or smaller a figure or object is compared to its original size when it is enlarged or reduced proportionally.
The formula is expressed as;
Scale factor = dimension of smaller shape/dimension of larger shape
Substitute the value, we have;
scale factor = 12/30
Divide the values
= 0.4
Then, we have;
0.4 = x/25
cross multiply the values
x =10