D. 16.8 units
A radius is half of the diameter, so to get the answer all you need to do is multiply the length of the given radius by 2.
8.4x2= 16.8
Answer:
The correct option is second one i.e 24 units.
Therefore the height of the triangle is

Step-by-step explanation:
Given:
An equilateral triangle has all sides equal.
ΔMNO is an Equilateral Triangle with sides measuring,

NR is perpendicular bisector to MO such that
.NR ⊥ Bisector.
To Find:
Height of the triangle = NR = ?
Solution :
Now we have a right angled triangle NRM at ∠R =90°,
So by applying Pythagoras theorem we get

Substituting the values we get

Therefore the height of the triangle is

I dont know, but someone ate my lefts overs >:(
Answer:
The answer is: 
Step-by-step explanation:
we are asked to subtract
from 
so,
.
Hence the desired result is:
.