measure of angle abc
Answers
Step-by-step explanation:
Given that,
In triangle ABC,m<A= 40°
Exterior angle at C = 100°
We know that,
Exterior angle of the triangle =Sum of its two opposite interior angle.
=>100°=m<A+m<B
=>100°-40°=m<B
=>m<B= 60°
Sum of angles of a triangle = 180°
=>m<A+m<B+m<C= 180°
=>100°+m<C=180°
=>m<C=180°-100°=80°
The 3 angles are 60°,40°& 80°
(Ans)
ANSWER:
/ ABC = 60°
Option (A) is the correct
(A) 60° ✔️
SOLUTION:
Given :
Find the measure of / ABC
To find the measure of / ABC
first we will find / ACB
/ BCA + 100° = 180°
(linear pair)
/ BCA = 180° - 100°
/ BCA = 80°
Now let's find the measure of / ABC
So , 40° + 80° + / ABC = 180°
(Angle sum property)
/ ABC = 180° - 120°
/ ABC = 60°
_____________________
Now let's verify our answer
/ ABC + / BCA + / CAB = 180°
RHS = 180°
Solving LHS
60° + 80° + 40°
180°
LHS = 180°
So, LHS = RHS
Hence , verified
___________________
Final answer :
/ ABC = 60°