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Recall the Base Angles Theorem, which states that in an isosceles triangle, the angles opposite the congruent sides are also congruent.
By the Consecutive Interior Angles Theorem, if two parallel lines are cut by a transversal, the consecutive interior angles are supplementary angles.
Recall the theorem that states that if a quadrilateral is a parallelogram, then its consecutive angles are supplementary.
The Law of Cosines relates the cosine of each angle in a triangle to its side lengths.
n = 4^(∘)
x = 18.5^(∘), y = 22.5^(∘)
w=18^(∘)
k=35
We are given the following diagram.
Let's take a look at the given diagram.
The diagrams shows a transversal passing through a pair of parallel lines. By the Consecutive Interior Angles Theorem, if two parallel lines are cut by a transversal, the consecutive interior angles are supplementary angles. Since the angles measuring 7x-19^(∘) and 3x+14^(∘) are consecutive interior angles, they must be supplementary.
Add terms
LHS+5^(∘)=RHS+5^(∘)
.LHS /10.=.RHS /10.
To find y, let's notice that the angles measuring 5y-2^(∘) and 7x-19^(∘) are vertical angles.
These angles are congruent by the Vertical Angles Theorem. In other words, they have the same measure. 5y-2^(∘) = 7x-19^(∘) We previously found that x = 18.5^(∘). Let's substitute this value for x and solve the resulting equation for y.
x= 18.5^(∘)
Multiply
Subtract term
LHS+2^(∘)=RHS+2^(∘)
.LHS /5.=.RHS /5.
Consider the given diagram.
For any triangle ABC, the Law of Cosines relates the cosine of each angle to the side lengths of the triangle.
We know the length of two sides, 25 and 15, and that the measure of their included angle is 120^(∘). We can use substitute this information into the Law of Cosines to write an equation in terms of k.
Note that we only kept the principal root when solving the equation because k is the length of a side and lengths cannot be negative.