2a.
Since BC = 10m and M is the midpoint, we can find CM by : 10÷2 = 5m
So, CM = 5m
2b. Now, you have the base ( 5m) & hypotenuse (13m). Pythagoras' Theorem:

Where c is the hypotenuse, a & b are sides.

b here refers to the height.
2c.
Area of a right-angled triangle =

So,
