Explicație pas cu pas:
a)AB=12cm
BC=20cm
teorema lui Pitagora:AB^2+AC^2=BC^2
12^2+AC^2=20^2
144+AC^2=400cm
AC=√400-144cm
AC=√256cm
AC=16cm
sinC=AB/BC=12/20=3/5cm
cosC=AC/BC=16/20=4/5cm
tgB=AC/AB=16/12=4/3cm
ctgB=AB/AC=12/16=3/4cm
b)AB=5cm
AC=5√3cm
AB^2+AC^2=BC^2
BC^2=25+75cm
BC^2=100cm
BC=√100cm
BC=10cm
sinB=AC/BC=5√3/10=√3/2cm
cosB=AB/BC=5/10=1/2cm
tgC=AB/AC==5/5√3=1✓3cm
ctgC=AC/AB=5√3/5=1✓3cm
c)AC=4cm
BC=2√6cm
AB^2+AC^2=BC^2
AB^2+4^2=2√6^2cm
AB^2+16=24cm
AB^2=24-16cm
AB^2=8cm
AB=√8cm
AB=2√2cm
sinB=AC/BC=4/2√6=2√6cm
sinC=AB/BC=2√2/2√6=1√3cm
tgB=AC/AB=4/2√2=2√2cm
tgC=AB/AC=2√2/4=√2/2cm