Question

va rog mult
măcar 3 exerciții sa faceti​

Answer 1

Răspuns:

Explicație pas cu pas:

12

∡A=40°                  ∡B=13/5·∡A=13·40/5=13·8=104°

∡C=(∡A+∡B)/2=(40°+104°)/2=144°/2=72°

∡D=360°-∡A-∡B-∡C=360°-(40°+104°+72°)=360°-216°=144°

13

∡B=2∡A    ⇒∡A=∡B/2

∡C=3/8∡B

∡D=∡C

∡A+∡B+∡C+∡D=360°

∡B/2+∡B+3∡B/8+3∡B/8=360°

4∡B+8∡B+6∡B=8·360°

18∡B=8·18·20     ⇒∡B=160°

∡A=80°

∡C=∡D=3·160°/8=60°

15

∡A=∡B=∡C=∡D    ⇒∡A=360°:4=90°

∡A=∡B=∡C=∡D=90°