Question

Cele doua exercitii
Dau coroana!!!!

Answer 1

$ctgC=\frac{AC}{AB} =\frac{\sqrt{2} }{2}$1.

∡A=90°

AB=45 cm

$cosinus=\frac{cateta\ alaturata}{ipotenuza}$

$cosB=\frac{AB}{BC} =\frac{3}{5}$

$\frac{45}{BC} =\frac{3}{5}$

BC=75 cm

2.

∡A=90°

AD inaltime

AD⊥BC

CD=10 cm

BD=20 cm

BC=BC+CD=30 cm

Aplicam teorema inaltimii (inaltime la patrat este egal cu produsul proiectiilor catetelor pe ipotenuza)

AD²=BC×CD

AD²=200

AD=10√2 cm

Aplicam Pitagora (suma catetelor la patrat este egala cu ipotenuza la patrat)

AB²=BD²+AD²

AB²=400+200

AB=10√6 cm

AC²=CD²+AD²

AC²=300

AC=10√3 cm

$sinus=\frac{cateta\ opusa}{ipotenuza} \\\\sinB=\frac{AC}{BC} =\frac{\sqrt{3} }{3} \\\\tg=\frac{cateta\ opusa}{cateta\ alaturata}\\\\ tgB=\frac{AC}{AB}= \frac{\sqrt{2} }{2}$

$cosC=\frac{AB}{BC}= \frac{\sqrt{3} }{6}$

Mai multe gasesti aici: https://brainly.ro/tema/5082897

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