The diagonals of a rhombus are in the ratio 3 :4. If the length of each side of the rhombus is 12.5 units, what is the length of the shorter diagonal?
15 units
Let the diagonals be 3k and 4k. Using the rhombus side formula: \(\left(\tfrac{3k}{2}\right)^2+\left(\tfrac{4k}{2}\right)^2 = 12.5^2\).
\(2.25k^2+4k^2=156.25 \Rightarrow 6.25k^2=156.25 \Rightarrow k^2=25 \Rightarrow k=5\).
Shorter diagonal: \(3k=15\) units.
Hence, the length of the shorter diagonal is 15 units.
Calculate the area of the triangle whose sides are 8 cm, 9 cm and 13 cm. (Rounded up to two decimal places)