9514 1404 393
Answer:
(c) 3√3
Explanation:
The altitude forms the long side of a 30°-60°-90° right triangle whose short side is 6/2 = 3 cm.
The ratios of side lengths in a 30°-60°-90° triangle are ...
1 : √3 : 2
Multiplying these ratio values by 3 gives the right triangle side lengths of ...
3 : 3√3 : 6
where 6 is the side length of the equilateral triangle. The length 3√3 is the altitude of that equilateral triangle.
The height of the triangle is 3√3 cm.