<em>Answer: h = 120 ft; w = 80 ft </em>
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<em>A = 9600 ft^2</em>
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<em>Step-by-step explanation: Let h and w be the dimensions of the playground. The area is given by:</em>
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<em>A = h*w (eq1)</em>
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<em>The total amount of fence used is:</em>
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<em>L = 2*h + 2*w + w (eq2) (an extra distance w beacuse of the division)</em>
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<em>Solving for w:</em>
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<em>w = L - 2/3*h = 480 - 2/3*h (eq3) Replacing this into the area eq:</em>
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<em>We derive this and equal zero to find its maximum:</em>
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<em> Solving for h:</em>
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<em>h = 120 ft. Replacing this into eq3:</em>
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<em>w = 80ft</em>
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<em>Therefore the maximum area is:</em>
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<em>A = 9600 ft^2</em>
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1. Given any triangle ABC with sides BC=a, AC=b and AB=c, the following are true :
i) the larger the angle, the larger the side in front of it, and the other way around as well. (Sine Law) Let a=20 in, then the largest angle is angle A.
ii) Given the measures of the sides of a triangle. Then the cosines of any of the angles can be found by the following formula:
a^{2}=b ^{2}+c ^{2}-2bc(cosA)
2.
20^{2}=9 ^{2}+13 ^{2}-2*9*13(cosA) 400=81+169-234(cosA) 150=-234(cosA) cosA=150/-234= -0.641
3. m(A) = Arccos(-0.641)≈130°,
4. Remark: We calculate Arccos with a scientific calculator or computer software unless it is one of the well known values, ex Arccos(0.5)=60°, Arccos(-0.5)=120° etc
Answer: 1326 students won't come to school
Step-by-step explanation:
All you have to do is find out 85% of 1560 which is 1326 students!
