Which object has more gravitational potential energy? use pe = m × g × h, where g = 9.8 meters/second2.

Gravitational potential energy can be calculated using the formula PE = m × g × h, where g is the gravitational acceleration and is constant hence the energy is dependent directly to mass and the height of the object. Hence more PE is registered when the object is heavier and/or at greater initial height. 

No because a circle or pie graph usually shows percentages you'd need a line graph