To find the distance \(d\) across the pond using the property of similar triangles, we need to establish a proportion based on the dimensions of the triangles.
In similar triangles, the ratios of corresponding sides are equal. Therefore, if we have two triangles, triangle \(FGH\) and triangle \(IJH\), we can express the relationship as follows, assuming \(FGH\) is the larger triangle that includes the pond and \(IJH\) is the smaller one that shares a height \(H\):
\[
\frac{\text{Base of triangle } FGH}{\text{Height of triangle } FGH} = \frac{\text{Base of triangle } IJH}{\text{Height of triangle } IJH}
\]
Let's use the variables:
- Let \(FG = d + x\) where \(d\) is the width across the pond and \(x\) is a known distance from point \(F\) to point \(I\).
- Let \(GH = H\) be the height of triangle \(FGH\).
- Let \(IJ = y\) be the base of triangle \(IJH\) (where \(y\) is a known measurement).
Then we could express it as:
\[
\frac{d + x}{H} = \frac{y}{h}
\]
Where \(h\) is the height from points \(I\) or \(J\) to the base of triangle \(IJH\) (which can also be a known distance).
We can rearrange this equation to solve for \(d\):
\[
d + x = \frac{y}{h} \cdot H
\]
\[
d = \frac{y}{h} \cdot H - x
\]
Now you just need to plug in the known values of \(x\), \(y\), \(H\), and \(h\) to calculate \(d\).
Since you did not provide specific measurements or a diagram, please fill in the relevant values in the equation. If you provide those values, I can assist you further in calculating \(d\).