A man has a rectangular garden, 55m ('B' in the diagram,) by 40m('A',) and he makes a diagonal path, 1m wide, exactly in the manner indicated in the diagram. What is the area of the path?
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The rectangle is 55 40 square meter. Each green triangle is 54 40/2 square meter. The difference is 55 40-2(54 40/2)= 40 square meter for the path ?
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Using the diagram above you are assuming AD = 1 m, it is actually AE that equals 1 m. AD is not the width of the path.
Longer side of the parallelogram shaped road is 66.66666666...m. Therefore it's area is (1)(66.6666666...)=66.66666..sq. m.
The rectangle is 55 40 square meter. Each green triangle is 54 40/2 square meter. The difference is 55 40-2(54 40/2)= 40 square meter for the path ?
4 0 csc ( θ ) /. Solve [ cot − 1 ( 4 0 1 ( 5 5 − csc ( θ ) ) ) = θ ∧ 8 π ≤ θ ≤ 2 π ] ≈ 6 6 3 2 .
I say approximately as I do not know to simplify the expression solved above to the necessary csc − 1 ( 3 5 ) .
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Label the path as follows and draw the width of the path intersecting A perpendicular to the path's edges:
Let x = A D . Then A C = 5 5 − x , and since B C = 4 0 , by Pythagorean's Theorem A B = 4 0 2 + ( 5 5 − x ) 2 .
Since D F ∣ ∣ A B , ∠ A D E ≅ ∠ C A B ; and since ∠ A E D and ∠ A C B are right angles, ∠ A E D ≅ ∠ A C B . Therefore, △ A E D ∼ △ A C B by AA similarity, and A E A D = B C A B , or 1 x = 4 0 4 0 2 + ( 5 5 − x ) 2 , which solves to x = 3 5 .
The shape of the path is a parallelogram, so when x = 3 5 its area is A B ⋅ A E = 4 0 2 + ( 5 5 − 3 5 ) 2 ⋅ 1 = 3 2 0 0 ≈ 6 6 . 6 7 m 2 .