Answer:
Option B) 4 centimeters
Step-by-step explanation:
see the attached figure to better understand the problem
step 1
Find the value of n
we know that
a) GJ is a midsegment of triangle DEF
then
G is the midpoint segment DF and J is the midpoint segment EF
DG=GF and EJ=JF
b) HK is a midsegment of triangle GFJ
then
H is the midpoint segment GF and K is the midpoint segment JF
GH=HF and JK=KF
In this problem we have
HF=7 cm
so
GH=7 cm
GF=GH+HF ----> by addition segment postulate
GF=7+7=14 cm
Remember that
DG=GF
substitute the given values

solve for n



step 2
Find the length of GJ
we know that
The <u><em>Midpoint Theorem</em></u> states that the segment joining two sides of a triangle at the midpoints of those sides is parallel to the third side and is half the length of the third side
so

we have

substitute

step 3
Find the length of HK
we have that
----> by the midpoint theorem
we have

substitute

2/3 x 5 = 3
the ratio from 4 to 20 is 5, then you multiply it by the original amount
so it's 3
Answer:
-20
Step-by-step explanation:
Complete the square to find the vertex of this parablola x^2-8x-y-4=0 {the second one of -20; so 4,-20}