See the attached picture to better understand the problem
we know that
in the right triangle ABC
cos 70=adjacent side angle 70/hypotenuse
adjacent side angle 70=BC----> <span>distance between the ladder and the tree trunk
hypotenuse=AC------> 15 ft
cos 70=BC/AC-------> solve for BC
BC=AC*cos 70------> BC=15*cos 70-----> BC=5.13 ft
the answer is
the </span>distance between the ladder and the tree is 5.13 ft<span>
</span>
we know that
in the right triangle ABC
cos 70=adjacent side angle 70/hypotenuse
adjacent side angle 70=BC----> <span>distance between the ladder and the tree trunk
hypotenuse=AC------> 15 ft
cos 70=BC/AC-------> solve for BC
BC=AC*cos 70------> BC=15*cos 70-----> BC=5.13 ft
the answer is
the </span>distance between the ladder and the tree is 5.13 ft<span>
</span>