Consider the circle $x^2+y^2+2x+4y-20=0and{x}^2+y^2+6x-8y+10=0$ Then which of the following is (are) true

$C_1=(-1,-2),r_1=5. C_2=(-3,4),r_2=\sqrt{15}. d=\sqrt{40}$   
$\therefore r_1+r_2>d>r_1-r_2$ Hence circles intersect at two district point then there are two common tangents exist
$2gg\text{'}+2ff\text{'}=-10,C+C\text{'}=-10\to$ Orthogonal
Length of common tangent $=\sqrt{d^2-{(r_1-r_2)}^2}=5{\left(\frac{12}{5}\right)}^{1/4}$ 
Length of common chord $=\frac{2r_1{r}_2}{\sqrt{{r_1}^2+{r_2}^2}}=5\sqrt{\frac{3}{2}}$