Answer:
10
Step-by-step explanation:
Since the triangles are similar then the ratios of corresponding sides are equal, that is
scale factor = [tex]\frac{PQ}{XY}[/tex] = [tex]\frac{3}{6}[/tex] = [tex]\frac{1}{2}[/tex]
That is the sides of Δ PQR are half those of Δ XYZ, thus
The perimeter of Δ PQR is half Δ XYZ, that is
perimeter of Δ PQR = [tex]\frac{1}{2}[/tex] × 20 = 10
