The perimeter of a rectangular plot of land is 250 meterr.If the length of one side of the plot is 40 meters,what is the area of the plot,in suqre meters.
Naomi makes silver jewelry.For one style of earrings,she cuts wedges from a silver disk,as shown in the figure above.Each wedge makes a 40° angle at the center of the disk.If the weight of each uncut disk is a unidormly distributed 2.5 grams,how many grams does each wedge weigh.
这两题有点看不懂,