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We can equate the expressions for the two angle measures and solve for x.
he diagram depicts a quadrilateral along with measures of its interior angles.
Now, recall the Polygon Angle-Sum Theorem.
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Polygon Angle-Sum Theorem |
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The sum of the measures of the interior angles of a convex n-gon is (n-2)*180^(∘). |
In this case, expressions are given for the measures of the interior angles. We can write an equation where the sum of these expressions is equal to (n-2)180. 116^(∘) + 3x+8^(∘) + 32^(∘) + 2x-1^(∘)= (n-2)180 Our polygon has 4 sides, so we can substitute 4 for n. 116^(∘) + 3x+8^(∘) + 32^(∘) + 2x-1^(∘) = (4-2)180^(∘) Finally, let's solve the equation above for x.
Add and subtract terms
Multiply
LHS-155^(∘)=RHS-155^(∘)
.LHS /5.=.RHS /5.
To find the value of x, we will need to use the Corresponding Angles Theorem.
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Corresponding Angles Theorem |
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If a transversal intersects two parallel lines, then corresponding angles are congruent. |
We can visualize this theorem. Consider two lines l and m, where l∥ m.
This allows us to find the measure of one of the angles with which the leftmost one forms a linear pair.
The measures of angles forming a linear pair must sum to 180^(∘). This allows us to write the following equation. 7x-3^(∘) + 4x+12^(∘) = 180^(∘) Let's solve this equation for x.