The Brainliest Answer!
As we know if we add 2 sides of triangle then it must be greater than the 3rd side so if the perimeter is 10.5 cm so angle L & angle M both must be e of 5 cm & angle K must be 0.5 cm & we also know that if we add all the angle the it must be 180 degree so if Angle L is 120 degree & Angle M is 30 degree means total is 150 degree so angle K must be of 30 degree as well .
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