Question

To prove angle A+B+C+D+E=180

Answer 1

Mark points as shown.

FROM ∆ABJ
A+B+J=180 (INTERIOR ANGLES OF TRIANGLE).

FROM ∆ABJ
E+C+G=180 (INTERIOR ANGLES OF TRIANGLE).

FROM ∆ABJ
D+E+I=180 (INTERIOR ANGLES OF TRIANGLE).

FROM ∆ABJ
B+D+F=180 (INTERIOR ANGLES OF TRIANGLE).

FROM ∆ABJ
A+H+C=180 (INTERIOR ANGLES OF TRIANGLE).

then,sum of all equations.
A+A+B+B+C+C+D+D+E+E+F+G+J+I+H=900
2(A+B+C+D+E)+F+G+J+I+H=900
2(A+B+C+D+E)=900-(F+G+J+I+H)
2(A+B+C+D+E)=900-540. SINCE, SUM OF ANGLES IN PENTAGON.
2(A+B+C+D+E)=360
A+B+C+D+E=360/2
THEREFORE,A+B+C+D+E=180.

Answer 2

Answer:

hope it helpful .please mark it brainlist