1. **Problem Statement:** We have an isosceles triangle KLM with sides KL = KM. Points L, M, and S are collinear with M between L and S. The exterior angle at vertex M, adjacent to the triangle, measures 115°. We need to find the measures of angles \(\angle L\) and \(\angle K\).
2. **Key Concept:** The exterior angle theorem states that an exterior angle of a triangle is equal to the sum of the two opposite interior angles. Here, the exterior angle at M is \(115^\circ\), so:
$$\angle L + \angle K = 115^\circ$$
3. **Isosceles Triangle Property:** Since \(KL = KM\), the base angles opposite these sides are equal. Therefore:
$$\angle L = \angle K$$
4. **Set up the equation:** Let \(x = \angle L = \angle K\). Then:
$$x + x = 115^\circ$$
$$2x = 115^\circ$$
5. **Solve for \(x\):**
$$x = \frac{115^\circ}{2} = 57.5^\circ$$
6. **Final answer:**
$$\angle L = 57.5^\circ$$
$$\angle K = 57.5^\circ$$
Thus, each named angle \(\angle L\) and \(\angle K\) measures 57.5 degrees.
Isosceles Angles
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