ABCD is a trapezium AD and BC are parallel
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Part (a)
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Work Shown:
We'll apply the sine rule since we have a known opposite side of AB = 10 and an unknown hypotenuse we want to find BD.
Focus on triangle ABD
sin(angle) = opposite/hypotenuse
sin(D) = AB/BD
sin(56) = 10/x
x*sin(56) = 10
x = 10/sin(56)
x = 12.062179
x = 12.1
Make sure your calculator is in degree mode.
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Part (b)
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Work Shown:
Draw an xy coordinate grid.
Place point A at the origin (0,0).
Point B is 10 units above this, so B is at (0,10).
Point C is at (18,10) since we move 18 units to the right of B.
Point D is at approximately (6.745085, 0). The 6.745085 is from solving tan(56) = 10/x for x.
Refer to the diagram below.
Apply the distance formula for the points C and D.
[tex]C = (x_1,y_1) = (18,10)\\\\D = (x_2,y_2) \approx (6.745085,10)\\\\[/tex]
[tex]d = \text{ distance from C to D}\\\\d = \sqrt{ (x_1-x_2)^2+(y_1-y_2)^2}\\\\d \approx \sqrt{ (18-6.745085)^2+(10-0)^2}\\\\d \approx \sqrt{ 226.673112 }\\\\d \approx 15.055667\\\\d \approx 15.1\\\\[/tex]
Segment CD is roughly 15.1 cm long.