Answer:

Explanation:
We have been given an image of triangle JKL. We are asked to find the measure of the exterior angle at vertex K.
Since measure of angle L is equal to measure of K, so we can find measure of these angles using angle sum property.




Since
, so using substitution property of equality we will get,




We know that measure of an exterior angle of a triangle is equal to the sum of the opposite interior angles.
So the measure of exterior angle at the vertex K will be equal to measure of angle J plus measure of angle L.


Therefore, the measure of the exterior angle at vertex K is 100 degrees.