Question 1165186
A median of a trapezoid is the segment that joins the midpoints of the nonparallel sides (legs)

I don't know how to draw trapezoid here sorry,
draw one where in
lower left (V) 
upper left (I)
upper right (O)
lower right (S)
between V and I (A) middle left
between S and O (C) middle right

really sorry don't know how to draw yet.

a) VA=5 find VI=?
{{{VI=2(VA)}}}
{{{VI=2(5)=10}}}

b) IO=10, VS=15 find AC=?
{{{AC(median)=(IO(short leg)+ VS (longleg))/2}}}
{{{AC=(IO+VS)/2}}}
{{{AC=(10+15)/2}}}
{{{AC=12.5}}}

c. If AC= 20, IO= x+3, VS= 3x+5, Find IO.
{{{AC=(IO+VS)/2}}}
{{{20=((x+3)+(3x+5))/2}}}
{{{40=(x+3)+(3x+5)}}}
{{{40=(4x+8)}}}
{{{32=4x}}}
{{{x=8}}}
{{{IO=x+3}}}
{{{IO=8+3=11}}}

HOPE THAT HELPS!
STAY SAFE!!