Question

incorporating variables
interior and exterior angles of a triangle
andrew colella

multiple - choice question
solve this equation. what do you get
for y?

( y = 5.2 )

( y = 17 )

( y = 15 )

Explanation:

Step1: Use exterior angle theorem

The exterior angle theorem states that an exterior angle of a triangle is equal to the sum of the two non - adjacent interior angles. So, \((5y + 3)+(4y + 8)=146\).

Step2: Combine like terms

Combine the \(y\) terms and the constant terms: \((5y+4y)+(3 + 8)=146\), which simplifies to \(9y+11 = 146\).

Step3: Isolate the term with \(y\)

Subtract 11 from both sides of the equation: \(9y+11-11=146 - 11\), so \(9y=135\).

Step4: Solve for \(y\)

Divide both sides by 9: \(y=\frac{135}{9}\).

Answer:

\(y = 15\)