Given data:
Diagonals if rhombus 15 inches and 20 inches.
Area of rhombus is,
[tex]A=\frac{1}{2}\times d1\times d2[/tex][tex]\begin{gathered} A=\frac{1}{2}\times15\times20 \\ A=150\text{inches sq} \end{gathered}[/tex]Now, to find the perimeter first find the side of the the rhombus
Diagonal is considered as diameter so radius will be the half of the diameter,
d1 = r1 = 7.5
d2 = r2 = 10
Finding the side by the pythagorean theorem,
[tex]\begin{gathered} h^2=(7.5)^2+(10)^2 \\ h^2=56.25+100 \\ h=12.5 \end{gathered}[/tex]Therefore, the perimeter of the rhombus is
[tex]\begin{gathered} P=4h \\ P=4\times12.5 \\ P=50\text{inches} \end{gathered}[/tex]Thus, the area is 150 in sq. and perimeter is 50 in.