Final answer:
In an isosceles triangle, the measure of angle K is equal to the measure of angle M. By setting up an equation and solving for x, we find that the measure of angle K is 60 degrees.
Step-by-step explanation:
In an isosceles triangle, the two base angles are equal. Since angle N is the vertex, the two base angles are angle K and angle M. Therefore, the measure of angle K is equal to the measure of angle M.
Let's denote the measure of angle K as x. Then, the measure of angle M is also x. Since the sum of the angles in a triangle is 180 degrees, we can write the equation:
x + x + angle N = 180.
Since triangle KNM is isosceles, angle N is x degrees. Thus, we can rewrite the equation:
2x + x = 180.
Combining like terms, we get:
3x = 180.
Dividing both sides by 3, we find:
x = 60.
Therefore, the measure of angle K is 60 degrees.