3x-4 is the answer, you have to see that if its 3 times her nieces age it would be 3x and if its four less than that it is 3x-4
Answer:
C
Step-by-step explanation:
x=60
60
60+30=90
60-30=30
60+90+30=180
The hypotenuse of the triangle is given by:

Substituting values:

Clearing CB we have:

Then, the perimeter of the triangle is:

Substituting values:
Answer: the perimeter of triangle BRC in units is: D.6 + 2√5