Question

an isosceles triangle has an angle that measures 100°. what measures are possible for the other two angles? choose all that apply. 70° 40° 5° 100°

Explanation:

Step1: Recall triangle angle sum

The sum of angles in a triangle is $180^\circ$.

Step2: Analyze isosceles triangle rules

An isosceles triangle has two equal angles. The given $100^\circ$ angle cannot be one of the pair of equal angles (since $100^\circ + 100^\circ = 200^\circ > 180^\circ$).

Step3: Calculate the equal angles

Let the equal angles be $x$. Set up the equation:
$$100^\circ + 2x = 180^\circ$$
Solve for $x$:
$$2x = 180^\circ - 100^\circ = 80^\circ$$
$$x = \frac{80^\circ}{2} = 40^\circ$$

Answer:

40°