Find the number of lines of symmetry in an isosceles triangle.

Consider the letters $\mathrm{A}$, $\mathrm{B}$, $\mathrm{D}$, $\mathrm{H}$, $\mathrm{S}$, $\mathrm{Z}$, $\mathrm{T}$, $\mathrm{O}$, $\mathrm{P}$, $\mathrm{L}$, $\mathrm{Y}$, $\mathrm{N}$. Which letter has horizontal line of symmetry other than $\mathrm{B}$, $\mathrm{D}$ and $\mathrm{H}$.

Consider the letters $\mathrm{B}, \mathrm{D}, \mathrm{S}, \mathrm{Z}, \mathrm{P}, \mathrm{L}, \mathrm{Y}, \mathrm{N}$. Write the letter which has a vertical line of symmetry.

Consider the letters $\mathrm{A}, \mathrm{B}, \mathrm{D}, \mathrm{H}, \mathrm{S}, \mathrm{T}, \mathrm{O}, \mathrm{Y}$. Write the letter which has no line of symmetry.