Question

trapezul isoscel ABCD ab|| cd are suma bazelor 18 cm diferenta bazelor 10 cm si inaltime 5 cm
A) Calculati aria trapezului
B) Calculati m(Bad)
C) Daca De||Bc, E∈ Ab si F ∈ De, asfel incat Be=BF calculati lungimea lui segmentului Cf

Answer 1

B+b=18
B-b=10    B=10+b
10+b+b=18
2b=18-10
b=8/2=4 baza mica
B+4=18
B=18-4=14 baza mare
A=(B+b)* in.)/2=18*5/2=90/2=45 cm^2
INALTIMEA=DM
AM=(AB-DC)/2=10/2=5
AD^2=5^2+5^2=25+25=50    AD= √50=5√2
sin A=DM/AD=5/5√2=1/√2=√2/2=45°=m(BAD)