Similar figures and congruent figures both have the same shape.
Two triangles are congruent if they are the same size and shape.
Congruency:They are exactly same in length, width, shape, size etc.
They are similar if they are the same shape (and maybe or maybe not the same size).
Also remember:
i. Every congruent pair of shapes is similar also.
ii. Not all similar figures are congruent though.
iii. The areas of two similar figures may be different.
iv. However, the areas of two congruent figures are equal.
v. Ratio of Corresponding Sides:
a. The ratios between the corresponding sides of two similar figures are equal.
b. The ratios between the corresponding bases of two congruent figures are always one.
vi. Symbol:
a. The symbol ≅ is for Congruent.
b. The symbol ~ is for Similar.
vii. Examples:
You went to a garment store to buy shirts. You liked one with black strips. You saw they were kept in various sizes: S, M, L, XL, XXL…
Now these shirts of different sizes are similar because they have the same shape.
But 2 shirts of the same size are congruent. They are exactly same in length, width, shape, size etc.
Two triangles are said to be similar to each other when they have same shape, proportion and angles but different sizes
Congruence on the other hand means when two things are exactly identical to each other.
The difference between similar figures and congruent figures is that congruent figures also have the same size. So, corresponding sides and corresponding angles of congruent figures have the same measures.