Question

va rog dau coroana am nevoie urgent​

Answer 1

Explicație pas cu pas

a)∆ADBdr.BD=AD

AB²=2BD²

BD =√2/2AB=10√2/2=5√2cm

∆ADC dr.sin 60°=DC/AC

√3/2=DC/12

DC=12√3/2=6√3cm

BC=BD+DC=5√2+6√3

perimetrul=10+12+5√2+6√3=22+5√2+6√3cm

Aria=BC×AD/2

aria=(5√2+6√3)×5√2/2=25×2/2+30√6/2=

25+15√6cm²

b) CD=DB

2CD²=CB²

CD=√2/2×4=2√2cm

<A=180-75-45=60°

tg 60°=CD/AD

√3=2√2/AD

AD√3=2√2

AD=2√6/3cm

sin 60°=CD/AC

√3/2=2√2/AC

AC=2√2/√3/2=4√6/3

Perimetrul=4√6/3+4+(2√6/3+2√2)=

6√6/3+2√2+4=2√6+2√2+4cm

Aria=AB×CD/2=