Area of a triangle is equal to 1/2 b(h) so since you already have the height and base, all you need to do is input it back into the equation:

(10)(13)
Multiply 10 & 13 to equal

(130)
Then take half of 130 to get
A = 65
The ratio of 186:76 can be simplified to 93:38 if we divide both numbers by 2.
The rock's height is increasing in the interval from 0 seconds to 3 seconds.
At time 0 the rock starts moving upward from 52 foot until it reachs 180 foot height (time 3 seconds). Then the rock starts to descend, which means that the height starts to decrease.
The answer for this question is 8/1