Practicing Success
In an equilateral triangle ABC, D is the midpoint of side BC. If the length of BC is 8 cm, then the height of the triangle is: |
5.5 cm 4.5 cm $6\sqrt{3}$ cm $4\sqrt{3}$ cm |
$4\sqrt{3}$ cm |
⇒ The median of an equilateral triangle bisects the base and makes \({90}^\circ\) so, So, BD = DC = \(\frac{B}{2}\) = 4 cm. Now, \( {AD }^{2 } \) + \( {DC }^{2 } \) = \( {AC }^{2 } \) ⇒ \( {AD }^{2 } \) + \( {4 }^{2 } \) = \( {8}^{2 } \) ⇒ \( {AD }^{2 } \) + 16 = 64 ⇒ \( {AD }^{2 } \) = 64 -16 ⇒ \( {AD }^{2 } \) = 48 ⇒ AD = 4\(\sqrt {3 }\) cm Therefore, the height is 4\(\sqrt {3 }\) cm |