Question

find the height of an equilateral triangle whose side is 15cm​

Answer 1

Explanation:

we can do this using Pythagoras theorem

i.e., AC^2=AB^2+BC^2

in the above figure

AB^2=BD^2+AD^2=> AD^2=AB^2-BD^2

so, h=√a^2-b^2

where, a=15cm & b=7.5cm

Answer 2

Answer

We know the side of the equilateral triangle which is 15 cm.

We know the formula of height of equilateral triangle which is

$\frac{ \sqrt{3} }{2} \: a = h$

Put the value of a

$\frac{ \sqrt{3} }{2} \times 15 = h \\ \\ \frac{15 \sqrt{3} }{2} = h \\ \\ 7.5 \sqrt{3} = h$

Put the value of root 3

$7.5 \times 1.73 = h \\ \\ 12.95 \: \: \: {cm}^{2} \: = h$