Answer
90 yards
Work Step by Step
The trigonometric ratios are as follows: $\sin \theta= \dfrac{opposite}{hypotenuse}$ ; $\cos \theta= \dfrac{Adjacent}{hypotenuse}$ and $\tan \theta= \dfrac{Opposite}{Adjacent}$
Let $ d $ be the difference in the height of the two buildings.
Height of the taller building $=d+40$ yards
Then: $ d=60 \times \tan 40^{\circ} \approx 50$ yard
So, height of the taller building is $50+40= 90$ yards
