Answer:
Given: R is the midpoint of QS.
QS=40
Now,
QR=40/2(R IS THE MIDPOINT)
=20
116*
Step-by-step explanation:
36* + 28* = 64*
180* - 64* = 116*
f=ab/a+b
Let's solve for f.
1/f=1/a+1/b