Question

Ajutoooorrr va ro pb 2

Answer 1

1. ABCD trapez isoscel cu AD=DC=BC=36cm<B=60⁰

?a)<ACD =180⁰-60⁰-30⁰=90⁰

b) perimetrul ABCD =AD+DC+BC+AB=

3×36+DC+2DC/2=108+2 DC=108+72=180cm

2.∆ ABC AD_l_ BC ;<C=30⁰

AC=12cm , BC=18cm

a)aria∆ ABC

in∆ ADC dreptunghic cu <C=30⁰

AD=AC/2=12/2=6cm

aria ∆ ABC= BC × AD/2=18×6/2=54cm²

b) distanța B la AC =BE

∆ CEB dreptunghic cu unghiul C=30⁰

BE=BC/ 2=18/2=9cm

3. trapez dreptunghic cu unghiul C=120⁰

DC=8cm BD bisectoarea lui<B

a) BC

∆ BCD isoscel deoarece <B= < C=30⁰

=> BC=DC=8cm

b) AB

∆dreptunghic CEB<B=60⁰

<C=30⁰=>EB=BC/2=8/2=4cm

=>AB=CD+EB =8+4=12cm