Part 3: Choose a proof method. 1. Use a paragraph, flow chart, or two-column proof to prove that is the perpendicular bisector of side .

Given: WZX YZX;

Prove: ZX is a perpendicular bisector of WY

The given congruences are corresponding sides and angles of ΔWZX and ΔYZX. Segment ZX is congruent to itself, so ΔWZX ≅ ΔYZX by SAS.

Then ∠WXZ ≅ ∠YXZ and WX ≅ YX by CPCTC. The latter means X is a midpoint and that ZX is a bisector of WY. The former means the angles of the linear pair ∠WXZ and ∠YXZ must both be 90°, as they are both congruent and supplementary.

Therefore, ZX is perpendicular to WY and also its bisector.

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.