The area of the rhombus is: $$$A=\frac{D \cdot d}{2}$$$
Its perimeter is: $$$ P=4 \cdot l$$$
Calculate the area of a rhombus with $$D = 1 \ m$$ and $$l = 0,7 \ m$$
- We find $$d$$ using the Pythagorean theorem using $$D$$ and $$l$$:
$$$ l^2= \Big(\frac{d}{2}\Big)^2 +\Big( \frac {D}{2}\Big)^2 \\ \Big(\frac{d}{2}\Big)^2= l^2-\Big(\frac{D}{2}\Big)^2 \\\Big(\frac{d}{2}\Big)^2=0,7^2 \ m^2-0,5^2 \ m^2=0,24 \ m^2 \\ d= 2 \sqrt{0,24} \ m = 0,98 \ m $$$
- The area is: $$$A=\frac{1 \ m \cdot 0'98 \ m}{2}=0,49 \ m^2$$$
And so, the area of the rhombus is: $$0,49 \ m^2$$.