Question

do questions 22 , 23 and 24

Answer 1

Q 23 - consider a point out of a line
Draw mainly three line from piont to line and measure all line only one line is 90 degree.
hence it is proved.
Q 24 angle apb is 90 because sum of other two angle of triangle is (180/2)=90.
because they are bisector of the two angle whose sum is 180.