Aregular pentagon has an apothem of 7.43 cm. find the length of a side of the pentagon and the length of the radius of the circumscribed circle

You have to figure it out.  First, the sum of the angles in a polygon = n-2(180) where n is the number of sides.  For a pentagon, this is 5-2(180)=540.  then divide by 5 for each of 5 large angles in the pentagon, and then divide by 2 for the angle formed by the radius in the right angle.  This is 540/5=108 divided by 2 = 54 degrees in the right angle.  Now that you know the angle , then use trig to solve the problem...