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Solve for x and y in the diagrams below.

Solve for x and y in the diagrams below.-example-1
User Amodrono
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1 Answer

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1. x = 13, y = 11.5

2. x = 39, y = 123

Step-By-Step Explanation: For the first diagram, you can see that 10x - 42 = 6x + 10 by way of vertical angles. Vertical angles are two opposite angles created by the same two lines, meaning that they will ALWAYS be congruent. Solving for x, you get that 4x = 52, or that x = 13. There is another thing. Both of the diagrams have a total angle measurement of 360, since they both go all the way around. Knowing that, 6x + 10 + 8y must be equal to half of that, or 180. Solving for 88 + 8y = 180 (since you know the value of x), you know that 8y = 92, or x = 11.5.

For number two, the concept is very similar, but this time there's more angles. You can immediately see that there are 3 pairs of vertical angles. The value of the angle squishes between the x - 10 and the 3x + 6 is x - 11; again, vertical angles. The angle squished between 3x + 6 and x - 11 is x - 10 (vertical angles!). Last, you know that 3 x + 6 = y, since they are vertical angles. Combining 2(x-11) and 2(x-10) and 2(3x+6) [remember, y = 3x + 6!!], you get that 10 x = 390, and x = 39. Plug that in for the value of y, which is 3x + 6, giving you 123 degrees.

User Falstro
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