Question

ABCD - trapez dreptunghic
AB ll CD
m ( ∡ B ) = m ( ∡ C ) = 90°
BC=CD=10cm
AB=2 CD
a). A=?
b). m ( ∡ A ) si m ( ∡ D )
c). P=?

Dau coronita
Va rog e urgent

Answer 1

AB ll CD
m ( ∡ B ) = m ( ∡ C ) = 90°
BC=CD=10cm
AB=2 CD = 2*10 =20 cm
a). A= (10+20)*10/2=150 cm²
b). m ( ∡ A ) si m ( ∡ D )
ducem DE perpendicular pe AB
obtinem triunghiul dreptunghic isoscel ADE  cu DE=AE=10 cm
deci m ( ∡ DAE ) = m ( ∡ ADE ) =90⁰:2=45⁰
m ( ∡ ADC ) =90⁰+45⁰=135⁰
 c).
AD=√(10²+10²)=√200=10√2
P=10+10+20+10√2=40+10√2 cm