Step-by-step explanation:
2.
to complete the description :
PQ || MN || BC
the midpoint theorem :
the line segment in a triangle connecting the midpoints of two sides of the triangle is said to be parallel to its third side and is also half of the length of the third side.
therefore,
MN connects the midpoints of AC and AB, and is therefore half of BC.
PQ connects the midpoints of AN and AM, and is therefore half of MN. and that is half of half of BC = one quarter of BC.
MN = 1/2 × BC
PQ = 1/2 × MN = 1/2 × 1/2 × BC = 1/4 × BC =
= 1/4 × 16 = 4 mm
3.
UV = 10 cm connects the midpoints of PT and PS, and is therefore 1/2 of TS.
in other words, TS = 2×UV = 2×10 = 20 cm.
now we go the other direction from Q :
TS connects to midpoints of QU and QR. therefore,
UR = 2×TS = 2×20 = 40 cm.
VR = UR - UV = 40 - 10 = 30 cm
