Answer:b
Step-by-step explanation:
Answer:
5
Step-by-step explanation:
A 30-60-90 triangle's sides equal as follows:
Hypotanuse= x (a number)
Long side= x/2( also can be calculated as x* 1/2) * 
Short side = x/2 or x * 1/2
3r-6=-21
3r-6+6=-21+6 (Add 6 to both sides...)
3r=-15
r=-5
3r-6=21
3r-6+6=21+6 (Add 6 to both sides...)
3r=27
r=9
r=-5 or r=9
One decimal place means one place after the decimal point, therefore you should round appropriately to get to one place after the decimal point.
The answer would therefore be 12.6 <span />
