how to solve question 17 i got this wrong so i lost 2 marks
Answers
Answer:
Step-by-step explanation:
Given:
AB is smallest side
CD is the longest side.
1) Proof to prove ∠A > ∠C
Construction:
Join A&C and mark the angles as shown in the attached figure - 1.
Proof:
In ΔABC,
BC > AB (∵ Angle opposite to longer side is greater)
=> ∠1 > ∠2. -------------- (E1)
In ΔADC,
CD > AD (∵ Angle opposite to longer side is greater)
=> ∠3 > ∠4 -------------- (E2)
Adding both these equations E1 and E2,
∠1 + ∠3 > ∠2 + ∠4
=> ∠A > ∠C
Hence proved.
2) Proof to prove ∠B > ∠D
Construction:
Join B&D and mark the angles as shown in the attached figure - 2.
Proof:
In ΔABD,
AD > AB (∵ Angle opposite to longer side is greater)
=> ∠5 > ∠6. -------------- (E3)
In ΔCBD,
CD > BC (∵ Angle opposite to longer side is greater)
=> ∠7 > ∠8 -------------- (E4)
Adding both these equations E3 and E4,
∠5 + ∠7 > ∠6 + ∠8
=> ∠B > ∠D
Hence proved.
