prove that angles opposite to equal sides of an isoscales triangle are equal
Answers
Answer:
Step-by-step explanation:
In the isosceles ∆XYZ, XY = XZ.
To prove ∠XYZ = ∠XZY.
Construction: Draw a line XM such that it bisects ∠YXZ and meets the side YZ at M.
Proof:
Statement
1. In ∆XYM and ∆XZM,
(i) XY = XZ
(ii) XM = XM
(iii) ∠YXM = ∠ZXM
2. ∆XYM ≅ ∆XZM
3. ∠XYZ = ∠XZY. (Proved)
Reason
(i) Given.
(ii) Common side.
(iii) XM bisects ∠YXZ.
2. By SAS criterion.
3. CPCTC.
Answer:
Prove that the angles opposite to equal sides of a triangle are equal.
ANSWER
ABC is a given triangle with, AB=AC.
To prove: Angle opposite to AB= Angle
opposite to AC (i.e) ∠C=∠B
Construction: Draw AD perpendicular to BC
∴∠ADB=∠ADC=90
o
Proof:
Consider △ABD and △ACD
AD is common
AB=AC
∴∠ADB=∠ADC=90
o
Hence ∠ABD=∠ACD
∠ABC=∠ACB
∠B=∠C. Hence the proof
This is known as Isosceles triangle theorem
solution.