Question

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

Explanation:

Step1: Recall triangle - angle sum property

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

Step2: Use equilateral - triangle property

In an equilateral triangle, all angles are equal. Let the measure of each angle be \(x\). Then \(x + x+x=180^{\circ}\).

Step3: Solve the equation

Combining like - terms gives \(3x = 180^{\circ}\). Dividing both sides by 3, we get \(x=\frac{180^{\circ}}{3}=60^{\circ}\).

Answer:

60°