Given: triangle xyz, segment xy is congruent to segment zy, and yw bisects angle xyz. prove that angle ywz is a right angle.

Step-by-step explanation:

YW bisects the angle XYZ (given)

considering Δ XYZ segment XY≅YZ given.

∠X≅∠Z angles of opposite equal sides are equal

a triangle having two equal sides is an isosceles triangle. Isosceles triangles have one 90 degrees angles as the total sum of the three angles of a triangle must equal 180 degrees.Therefore ∠Y=90 degrees

but segment YW bisects the angle Y so ∠ZYW= 45 degrees but ∠Z=45 degrees (ΔXYZ is a right angled isosceles triangle)

so ∠YWZ=90 degrees as ΔYWZ is also right angled isoseles triangle having two sides equal to 45 and third = 90 degrees.

Hence segmnet YW is perpendicular on segment XZ

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13