Question

Va rog daca ma poate ajuta cineva ​

Answer 1

2.

intr un paralelogram unghiurile opuse sunt egala doua cate doua
m∡A=m∡C=40°
m∡B=m∡D=360°-80°):2=140°

suma unghiurilor alaturate este de 180°
m∡A/6=m∡B/4=k⇒m∡A=6k m∡B=4k
m∡A+m∡B=180°⇒6k+4k=180°⇒k=18
m∡A=104° m∡B=72°
m∡C=104° m∡D=72°

m∡A=3m∡B⇒m∡A=135°
m∡A+m∡B=180°⇒m∡B=180°:4⇒m∡B=45°
si vezi unghiurile opuse

m∡A*5=m∡B*7=k(din A/1/5 si B/1/2)
m∡A=k/5 m∡B=k/7
k/5+k/7=180°⇒7k+5k=180*35⇒12k=180*35| :12
⇒k=525
m∡A=525/5=105° m∡B=525/7=75°
si vezi unghiurile opuse
3.

P ABCD = AB+BC+CD + AC /

AB = CD = 2 cm
BC = AC=6 cm
P ABCD = 2cm + 2 cm 6cm + 6 cm = 4 cm +12 cm = 16 cm

AB= DC = 34 cm
BC= AD = 17 cm
P ABCD = 34 cm +34 cm +17 cm +17 cm = 102 cm


p = 13,5 cm
p= P:2
P= 2× p
P = 2×13,5 cm
P = 27 cm