Subjects geometry

Isosceles Angles

Step-by-step solutions with LaTeX - clean, fast, and student-friendly.

Use the AI math solver

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.