Explanation:
Find the slope of JK by the formula :y2-y1/(x2-x1) whose value is 4/5
similarly, calculate the slope of GH it's value is also 4/5
Find slope of GK now by same formula y2-y1/( x2-x1 ).the value will be -5/3
Similarly calculate slope of HJ and you will get its value to be -5/3
since parallel lines have equal slopes JK and GH are parallel and GK and HJ are parallel. Since opposite sides are parallel GHJk is parallelogram