The sector area is equal to half of the product of the sector arc length and the sector radius. Let s be the sector area, l be the sector arc length and R be the sector radius=______ ．

The sector area is equal to half of the product of the sector arc length and the sector radius. Let s be the sector area, l be the sector arc length and R be the sector radius=______ ．

The answer is: 12lr

It is known that the circumference of a sector is C (c > 0). When the arc length of a sector is what, it has the largest area? And get the maximum area

Let R be the radius of the sector and l be the arc length, then C = 2R + L and R = C − L2, so the area of the sector s = 12rl = - 14l2 + 14cl. It can be seen that when l = C2, the area of the sector s has the maximum value of c216. When the arc length of the sector is C2, it has the maximum area and the maximum value of the area is c216. So the answer is: C2, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; c216