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Using ΔJKL, what is the measure of angle K?

Using ΔJKL, what is the measure of angle K?-example-1
User Nam Lee
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1 Answer

3 votes

Answer:

x = 34.5

Explanation:

Did you mean to upload a different problem with a triangle? If so, just ignore my answers. If not, then my explanation will show you how to find x in the picture you provided.

Step 1: Find the measure of the angle across from the 40° angle:

  • It appears that the traversal intersecting lines m and n make them parallel.
  • When two straight lines intersect, they create vertical angles, which are two angles opposite each other.
  • Vertical angles are always congruent and thus equal.
  • The traversal intersects line m and thus the 40° angle and angle opposite it are vertical angles.

Thus, the measure of the angle opposite the 40° angle is also 40°.

Step 2: Find x by applying the Same-Side Interior Angles Theorem:

  • The Same-Side Interior Angles Theorem says that when a traversal intersects two parallel lines, the same-side interior angles are supplementary and thus their sum equals 180°.

Thus, we can find x by setting the sum of the 40° we just found and the (4x + 2)° equal to 180:

40 + 4x + 2 = 180

42 + 4x = 180

4x = 138

x = 34.5

Thus, x = 34.5

When you plug in 34.5 for x, we see that the measure of the angle is 140° as 4(34.5) + 2 = 140.

User Rosalyn
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