If a+b=2h , then the area of the triangle formed by the lines ax2+2hxy+by2=0 and the line x-y+2=0 in square units is

The area of the triangle formed by the lines ax2+2hxy+by2=0 and lx+my+n=0 is n2h2-abam2-2hlm+bl2Here a=a,2h=2h,b=b,l=1,m=-1,n=2Substitute the appropriate values in the above formula and then use the condition  a+b=2h Hence, the required area is 4h2-aba+2h+b=4a+b24-aba+b+a+b=a-ba+b