standard_description: Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.
problem_activity: Triangle
$${{{CDE}}}$$
underwent a transformation that created triangle
$${{{C'D'E'}}}$$
.
[IMG]
a.   Describe how triangle
$${{{CDE}}}$$
was transformed to become triangle
$${{{C'D'E'}}}$$
.
b.   What features stayed the same?
c.   What features changed?
d.   Is triangle
$${{{CDE}}}$$
congruent to triangle
$${{{C'D'E'}}}$$
? Explain how you know.


aligns: no