<h3>9)</h3><h3>5 planes</h3>
<h3>10)</h3><h3>2 planes</h3>
<h3>11)</h3><h3>BCED</h3>
<h3>12)</h3><h3>Yes , they belong to plane (w)</h3>
See the picture to better understand the problem
we know that
in the triangle ABC
∠A+∠B+∠C=180°
find ∠C
∠C=180-[80+65]------> ∠C=35°
Applying the law of sines
AB/sin C=CB/sin A
solve for CB
CB=AB*sin A/sin C-----> CB=45*sin 65/sin 35-----> CB=71.10 ft
the answer is<span>
the distance from person B to the top of the hill is 71.10 feet</span>