Answer:
P=41.72
Step-by-step explanation:
S=ACxDB/2
81.7=8.6xDB/2
81.7=4.3xDB|:4.3
19(mm)=DB
DO=19/2=9.5
OC=8.6/2=4.3
(O is the center of the rhombus, where two diagonals meet)
a²+b²=c² (DO²+OC²=DC²)
9.5²+4.3²=c²
90.25+18,49=c²
√108,74=√c²
c≈10.43
P=4c
P=4x10.43
P=41.72
Hope it helps:)
