**1. What is the plural of vertex?**

Vertices. A triangle has three vertices (corners)

.

**2. What is the difference between an ALTITUDE and a MEDIAN in a triangle?**

An

ALTITUDEis a line from a vertex which meets the opposite side (or its extension) at right angles.

AMEDIANis a line from the vertex to the mid-point of the oppsoite side.

**3. What is the difference between SIMILAR triangles and CONGRUENT triangles ?**

SIMILARtriangles have the same shape butdifferentsize.

CONGRUENTtriangles are the same shape andsamesize.

**4. Is the longest side of a triangle always opposite the biggest angle?**

Yes, and the

SMALLESTangle is always opposite theSHORTESTside.