Question 9.2E4: Congruent Triangles Triangles ABC and A′B′C′ in Fig. 9.23 ar......

Because ΔABC is congruent to ΔA′B′C′, we know that the corresponding side lengths are equal and corresponding angle measures are equal.

a)  A′C′ = AC = 13                              b)  AB = A′B′ = 10.6
c)  m∡C^′A^′B^′  =  m∡CAB = 60°        d)  m∡ACB  =  m∡A^′C^′B^′ = 50°
e)  The sum of the angles of a triangle is 180°. Since m∡BAC = 60° and m∡ACB = 50°, m∡ABC = 180° – 60° – 50° = 70°.