Question

problem 9: spiral review determine the missing angle measure in the equilateral triangle. show or explain your thinking.

Explanation:

Step1: Recall angle - sum property of a triangle

The sum of the interior angles of a triangle is 180°.

Step2: Note properties of an equilateral triangle

In an equilateral triangle, all angles are equal. Let the measure of each angle be \(x\).

Step3: Set up an equation

We have \(x + x+x=180^{\circ}\), which simplifies to \(3x = 180^{\circ}\).

Step4: Solve for \(x\)

Dividing both sides of the equation \(3x = 180^{\circ}\) by 3, we get \(x=\frac{180^{\circ}}{3}=60^{\circ}\).

Answer:

\(60^{\circ}\)