Triangle Time

Write a function triangle_area that takes the base and height sizes of a triangle and returns its area.

(Reminder, the area of a triangle is 1/2 * base * height).

Sample Input 1:

base is 5 height is 6

Sample Output 1:

15.0

Sample Input 2:

base is 3 height is 4

Sample Output 2:

6.0

Sample Input 3:

base is 1 height is 2

Sample Output 3:

1.0