Before you study how to convert mixed fraction into decimal, you are adviced to study:
Define Line Segment
Define Vertex
Definition: A line segment joining the vertex of a triangle to the midpoint of its opposite side is known as Median of the Triangle
Or we can say that:
Median connects a vertex of a triangle with midpoint of its opposite side.
Example  In the below Triangle PQR
Point X is the midpoint of side RP.
Side RP is opposite to Vertex Q
And QX is a line segment which connects Vertex Q and with X
Hence, Line Segment QX is a Median of Triangle PQR
Example 2: How many medians can a triangle have ?
Solution: As we know that a triangle has three vertices and three sides.
And a median connects a vertex and opposite side.
Therefore we can say that there can be three medians in a triangle.
In the below triangle ABC:
Vertices A, B & C are connected to the midpoints Q, R & P of their respective opposite side BC, AC and AB.
Therefore, we got three Medians: AQ, BR & CP in Triangle ABC

