Hence using Angle sum property, we can find out the measure of Angle A.
⇒ ∠A + ∠B +∠C = 180°
⇒ ∠A + 50° + 70° = 180°
⇒ ∠A + 120° = 180°
⇒ ∠A = 180° - 120°
⇒ ∠A = 60°
Now consider Δ ABC and Δ DEF
∠A = ∠D = 60° (A)
BC = EF (Given) (S)
∠C = ∠F (Given) (A)
Hence by ASA Congruence rule,
Δ ABC ≅ Δ DEF
Hence they are congruent triangles.
Q2 ) Since only 1 angle and 2 sides are given, we must check whether the given triangle satisfies SAS congruence.
But on looking deeply, we can see that: Angle marked in the diagram is not included between the sides. That is, The Angle 80 degrees is in the opposite of side 4 cm. If it was in between 3 cm and 4 cm, then it would been SAS Congruence.
But since it is not in between ( non inclusive angle ), the given Δ LMN and Δ RST are not congruent.
Answers & Comments
Answer:
Q1 ) Let's consider Δ ABC first.
It is given that:
Hence using Angle sum property, we can find out the measure of Angle A.
⇒ ∠A + ∠B +∠C = 180°
⇒ ∠A + 50° + 70° = 180°
⇒ ∠A + 120° = 180°
⇒ ∠A = 180° - 120°
⇒ ∠A = 60°
Now consider Δ ABC and Δ DEF
Hence by ASA Congruence rule,
Δ ABC ≅ Δ DEF
Hence they are congruent triangles.
Q2 ) Since only 1 angle and 2 sides are given, we must check whether the given triangle satisfies SAS congruence.
But on looking deeply, we can see that: Angle marked in the diagram is not included between the sides. That is, The Angle 80 degrees is in the opposite of side 4 cm. If it was in between 3 cm and 4 cm, then it would been SAS Congruence.
But since it is not in between ( non inclusive angle ), the given Δ LMN and Δ RST are not congruent.
Hence they are non - congruent triangles.
Answer:- See the above attachment
plz help me mods I don't know why I can't post this ans with text... plz help see the 2nd attachment