Triangle ABC is rotated 45° about point X, resulting in triangle EFD. Triangle A B C is rotated 45 degrees about point X to form
triangle E F D. The lengths of sides A C and D E are congruent, the lengths of sides A B and E F are congruent, and the lengths of sides D F and C B are congruent. If EF = 4.2 cm, DF = 3.6 cm, and DE = 4.5 cm, what is CB? 3.3 cm 3.6 cm 4.2 cm 4.5 cm
Here, triangle ABC is rotated about point X which results in triangle EFD. Since triangle ABC is rotated it retains its shape and dimensions. This means that triangle ABC is parallel to triangle EFD ie, ABC≈EFD, also both dimensions will be congruent.
Thus
AB = EF
BC = FD
AC = ED
CB = DF
BA = FE
CA = DE
Since length of side DF = length of side CB, and DF = 3.6 cm. Therefore, CB = DF = 3.6 cm
You get this because whenever there are three digits after a number you add a comma as seen in the number there are three digits after 85 so you add a comma.
Perimeter is the addition of all 4 sides and a square as all the same sides. so every side will be the same. so if you divide 216 by 4 you get 54. you can check this by adding 54+54+54+54=216 or 54x4=216
