Question

a circular field is to be fenced having it turns of wire 3520 wire is required for this purpose find the radius of field and its area in ares​

Answer 1

Circumference =2πr=3520×7÷2×22=

560m radius

Answer 2

Answer: 25

Step-by-step explanation:

This is a very simple question. Let M be the angle, the arc of the sector AOB makes with the center O. Let OA = OB = radius r.

Given

OA+arcAB+OB=20

2r+rM=20

M=20−2rr

Area A of the sector =M2r2=10r−r2

dAdr=10−2r=0

r=5

Second derivative is negative for r=5

We get maximum area at r=5

A=25