Ur whole be a for the following reasons
The last one is correct because 60+35+35+35=165
55+55+55=165
Answer:
c = 
Step-by-step explanation:
Given
R= 
Clear the radical by squaring both sides
R² = b² - 4ac ( subtract b² from both sides )
R² - b² = - 4ac ( multiply all terms by - 1 )
b² - R² = 4ac ( divide both sides by 4a )
= c
2 because there are 4 numbers of edges and 4 vertices