On day 61, we focus our attention on the Congruence criteria for triangles. There will be questions that ask you to state why two triangles are identical. Here you will need to examine the side lengths and angles of the triangle and see which of the four categories they fit into. Side, Side, Side (SSS), Side, Angle, Side (SAS), Angle, Side, Angle (ASA), Right Angle, Hypotenuse, Side (RHS).

You may have to flip/rotate the triangles in your head (or use tracing paper) to see if they match up and identify which criterion to use.

In today's blog, we are taking a look at Similarity and Congruence. Starting with congruence, the key thing to remember is that congruent shapes are IDENTICAL all sides are the same length and all angles are the same. The shapes may have been altered slightly so you might have to rotate, flip them so that they match up.

With similar shapes, it is important to understand that all angles remain the same and it is the side lengths that have been altered (essentially, similar shapes are ENLARGEMENTS of each other). You will have to calculate the scale factor in order to find missing values between the shapes.

When confronted with area and volume problems of similar shapes you must square or cube the scale factor to get the correct answer.