Two diagonals are not necessarily equal in a/an

The lengths of diagonals of a rhombus are $18 \mathrm{cm}$ and $24 \mathrm{cm}$. The length of each side of the rhombus is

If a triangle has a base of $7\frac{3}{4} \mathrm{cm}$ and its height is$11\frac{3}{4} \mathrm{cm}$, and its area is expressed as $k\frac{l}{m} {\mathrm{cm}}^2$in the simplest form. Find the value of $k.$ 

Find the perimeter of a quadrilateral whose four sides are $3\frac{1}{2} \mathrm{cm}, 5\frac{5}{12} \mathrm{cm}, 3\frac{3}{4} \mathrm{cm}$ and $4\frac{1}{6} \mathrm{cm}$.

Aditya travelled $2\frac{1}{4} \mathrm{km}$ from home to school, $3\frac{1}{2} \mathrm{km}$ from school to the post office, $5\frac{3}{4} \mathrm{km}$ from the post office to the market and $2\frac{1}{8} \mathrm{km}$ from the market to his home. If Aditya travelled $\frac{k}{8} \mathrm{km}$, then find the value of $k$.

Two supplementary angles differ by $20°$. Find the measure of each angle

Represent the situation algebraically. Two-third of a number is $4$ more than $6$ .

Represent the situation algebraically. The denominator of a rational number is greater than its numerator by $4$. If the numerator is increased by $11$ and the denominator is decreased by $1$, the new number becomes $\frac{7}{3}$.

The exterior angle of a regular polygon is one-third of its interior angle. How many sides has the polygon?