Answer:
<h3>the answer is 21 </h3>
Step-by-step explanation: i did the quiz
Given:
height = 6m
chord = 20 m
We need to find the radius of the circle.
20 m = 2 √ [ 6m( 2 x radius - 6 m ) ]
20 m / 2 = 2 √<span>[ 6m( 2 x radius - 6 m ) ] / 2 </span>
10 m = √<span> [ 6m( 2 x radius - 6 m ) ] </span>
(10 m)² = √[ 6m( 2 x radius - 6 m ) ] ²
100 m²<span> = 6 m( 2 x radius - 6 m ) </span>
100 m²<span> = 12 m x radius - 36 sq m </span>
100 m² + 36 m² = 12 m x radius - 36 m² + 36 m²
136 m²<span> = 12 m x radius </span>
136 m²<span> / 12 m = 12 m x radius / 12 m </span>
<span>11.333 m = radius
</span>
the area beneath an arc:
<span>Area = r</span>²<span> x arc cosine [ ( r - h ) / r ] - ( r - h ) x </span>√<span>( 2 x r x h - h</span>²<span> ).
</span>
<span>r</span>²<span> = (11.333 m)</span>²<span> = 128.444 m</span>²<span> </span>
<span>r - h= 11.333 m - 6 m = 5.333 m </span>
<span>r * h = 11.333 m x 6 m = 68 m</span>²
<span>Area = 128.444 m</span>²<span> x arc cosine [ 5.333 m / 11.333 m ] - 5.333 m x </span>√<span>[ 2 x 68 m</span>²<span> - 36 m</span>²<span> ] </span>
<span>Area = 128.444 m</span>²<span> x arc cosine [ 0.4706 ] - 5.333 m x </span>√<span> [ 100m</span>²<span> ] </span>
<span>Area = 128.444 m</span>²<span> x 1.0808 radians - 5.333 m x 10 m </span>
<span>Area = 138.828 m</span>²<span> - 53.333 m</span>²<span> </span>
<span>Area = 85.4 m</span>²
A, B and c are all answers
90 for the box and 45 for the next angle
