Vocabulary consisting only from characters you are able to read
正三角形
seisankakkei
equilateral triangle, regular trianglemath
第三者
daisansha
third party/third person/outsider/disinterested person/(P)leda1
航空機
koukuuki
aircraft, aeroplane, airplanemix
礼
rei
thanking/expression of gratitude/(P)jlpt3