Question

Part 4. Find the missing sides for the 30 60 90 triangles. Please show work for each​

Answer 1

10. (l, y) = (6, 12)

11. (c, w) = (9√3, 18√3)

12. (x, y) = (12√3, 24√3)

Explanation:

Side ratios, shortest to longest, in a 30°-60°-90° triangle are ...

1 : √3 : 2

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10. l : 6√3 : y = 1 : √3 : 2

multiply by 6

= 6 : 6√3 : 12

l = 6, y = 12

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11. c : 27 : w = 1 : √3 : 2

multiply by 27/√3 = 9√3

= 9√3 : 27 : 18√3

c = 9√3, w = 18√3

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12. x : 36 : y = 1 : √3 : 2

multiply by 36/√3 = 12√3

= 12√3 : 36 : 24√3

x = 12√3, y = 24√3

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This is easier when the triangle is drawn to clearly differentiate the lengths of the sides. The long leg is opposite the 60° angle; the short leg is opposite the 30° angle.

Answer 2

10. tan(30) = l / 6√3

l = tan(30) x 6√3

l = 6

cos(30) = 6√3 / y

y = 6√3/cos(30)

y = 12

11. tan(30) = c/30

c = 30 x tan(30)

c = 10√3

cos(30) = 27/w

w = 27/cos(30)

w = 18√3

12.

sin(60) = 36/y

y = 36/sin(60)

y = 24√3

tan(60) = 36/x

x = 36/tan(60)

x = 12√3