Only the or part of Q. 31.
Pls solve both the question. Urgent
Answers
Answer:
I will answer both questions of 31
1)Given:A triangle ABC
To prove:angle A+angle B+angle C=180
Construction:Draw a line DAE||BC
Proof:DAE||BC & AB is transversal
hence,angle DAB(4)=angle ABC(2)
DAE||BC &AC is transversal
hence,angle EAC(5)=angle ACB(3)
Now,4+5+angle BAC(1)=180 (DAE is a straight line)
=)2+3+1=180
hence, it is proved that the sum of all angles of triangle is 180
2) Since,AM is the inspector of angle BAM.
angle BAM=angle CAM
In triangle ABN, angle ANB=90
Hence, angle ABN+angle BAN=90
angle ABN=(90-angle BAN)
angle B=(90-angle BAD) (2)
SIMILALY,angle C=(90-angle CAN) (3)
On subtracting ( 3) from (2)
angle B-angle C=(90-BAN)-(90-CAN)
=CAN-BAN
=(CAN+NAM)-(BAN-NAM)
=2NAM
Hence,angle NAM=1/2×(B-C)
Bro, Mark it as Brainlist answer,I need it