In the triangle ABC, AB=AC and angle BAD =angle CAD. Show that
(a) angle BAD is congruent to angle CAD
(b) BD =CD
(c) angle ADB= angle ADC=90°
Answers
Answer:
just a sec
Step-by-step"
Given
AB =AC....... 1
angle BAD =angle CAD.........2
in ∆BAD & ∆CAD
AB = AC........ given(1)
angle BAD =angle CAD...... given (2)
AD = AD......... common
hence
∆BAD is congruent to ∆ CAD
by SAS congruent rule.
a) angle BAD is congruent to angle CAD
.......[ by C. P. C. T]
b) BD =CD .......[ by C. P. C. T]
c)
angle ADB= angle ADC .......[ by C. P. C. T]..... 3
angle ADB + angle ADC =180°........ 4
( angel sum property of a linear line)
from 3
angle ADB= angle ADC
therefore
angle ADB + angle ADB =180°
2 * angle ADB =180°
angle ADB =90°
put in eq 4
angle ADB + angle ADC =180°
90° + angle ADC =180°
angle ADC = 90°
hence
angle ADB= angle ADC=90°
Step-by-step explanation:
BY SAS RULE
ANGLE BAD=ANGLE CAD