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Find the value of x in the triangle shown below: 7,7,9 and 80 degrees and x

User Joshlf
by
3.3k points

1 Answer

6 votes

Answer:

50

Explanation:

Step 1: Recognizing that we have an isosceles triangle

This is an isosceles triangle because it has two congruent sides(two sides with a length of 7). The angles across from the congruent sides are also congruent, so the angle without a label measures x∘

x, degrees:

Hint #22 / 4

Step 2: Writing an equation

The three angles in a triangle add up to 180 180 ∘

180, degrees. We can write this as an equation:

x + x + 80 = 180∘

+x ∘

+80 ∘

=180 ∘

x, degrees, plus, x, degrees, plus, 80, degrees, equals, 180, degrees

Hint #33 / 4

Step 3: Solving for x

x+x+80

2x+80

2x+80−80

2x

2

2x

x

=180

=180 Simplify the left-hand side

=180−80 Subtract 80 from each side

=100

=

2

100

Divide each side by 2

=50

Hint #44 / 4

The answer

x = 50

User Alan Cole
by
3.8k points