Given:
ZY=90 ft, YX=672 ft, and ZX=678 ft.
WY=t
The line segment WY is perpendicular to the side ZX from the third vertex Z.
So WY is the altitude of the given triangle.
Let a=90 ft, b=672 ft and c=678 ft, and t is altutude.
The formula for the altitude is
![t=\frac{2\sqrt[]{s(s-a)(s-b)(s-c)}}{b}](https://img.qammunity.org/2023/formulas/mathematics/college/ae0y75i3fk52n41ygcznuy8mm7yq5sny9x.png)
Here s is the semiperimeter of the tirangle .

Substitute a=90ft, b=672, and c=678 in the equation , we get

We get s=720ft.
Substitute s=720ft, a=90ft, b=672, and c=678 in the altitute formula, we get
![t=\frac{2\sqrt[]{720(720-90)(720-672)(720-678)}}{672}](https://img.qammunity.org/2023/formulas/mathematics/college/38kc5d48tzv7klp7aoideqi4qofrm3tdvl.png)
![t=\frac{2\sqrt[]{720*630**48*42}}{672}](https://img.qammunity.org/2023/formulas/mathematics/college/pjag74w3ui3c315lk30krctjxl1am191vt.png)
![t=\frac{2\sqrt[]{914457600}}{672}=90](https://img.qammunity.org/2023/formulas/mathematics/college/s3nk01pzfxefzebi3e65z9gbtwdgjsgijq.png)
Hence the value of the variable is 90 ft.