Prove that the sum of the measures of angles of a truangle is 180°

to prove that the sum of the triangles is equal to 180 degree

we have to take three angles angle 1 2 and 3 angle 1 is equal to angle p angle 2 = q and angle 3 is equal to r

and we have to prove that angle 1 + angle 2 + angle 3 is equals to 180 degree

construction draw a line xy passing through

p parallel to QR

proof

for for lines xy and QR with transversal PQ x p q is equals to4 and YPR is equals to angle5

so angle 2 is equal to angle 4 alternative angles

angle 5 is equal to angle 3 alternative angles

also fore line xy angle 1 + angle 4 + angle 5 is equals to 180 degree

and angle 1 + angle 2 + angle 3 is equal to 180 degree

hence sum of all triangles is equal to 180 degree

hence proved

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.