Ican't seem to figure out number 13, with the star. i just don't know! is very appreciated ☺️

Given:
Scale of the map 1 1/4cm : 8 yards
Rectangular Park:  width : 2 1/2 cm ; length : 6 1/4 cm
Circular Pond: pi = 3.14 ; diameter 1 1/4 cm

Convert mixed factions into fractions.
Scale 1 1/4 = (4*1+1)/4 = 5/4
Width: 2 1/2 = (2*2+1)/2 = 5/2
Length: 6 1/4 = (4*6+1)/4 = 25/4
Diameter: 1 1/4 = (4*1+1)/4 = 5/4

width / scale * 8 yds = width in yards
5/2 ÷ 5/4 = 5/2 * 4/5 = 20/10 = 2 * 8 yds = 16 yds
length / scale * 8 yds = length in yards
25/4 ÷ 5/4 = 25/4 * 4/5 = 100/20 = 5 * 8 yds = 40 yds

Area of a rectangular park = l * w = 40 yds * 16 yds = 640 yds² 
 
diameter / scale * 8 yds = diameter in yards
5/4 ÷ 5/4 = 5/4 * 4/5 = 20/20 = 1 * 8 yds = 8 yds.

radius = d/2 = 8/2 = 4
Area of a circular pond = πr² = 3.14 * 4² = 3.14 * 16yds² = 50.24 yds²

The answer would be (c)