We can verify our answer by substituting the value of "h" in (h + 1) to determine the height of the triangle. Then we can substitute the height and the base in the "area of triangle" formula (1/2 x Base x Height).
Note: Keep in mind that the evaluated area should be 18 cm², as said in the question. If the area evaluated is different from 18 cm², then the value of "h" is incorrect.
<u>Verifying our answer through mental math:</u>
Clearly, the height of the triangle is 6 cm, as when "h" is substituted in the expression (h + 1), we get 5 + 1.
As said above, the formula for determining the area of a triangle is 1/2 x Base x Height. Clearly, half of 6 is 3.
Lastly, when 6 (Base) and 3 (Half of the height) are multiplied, we get 18 cm², which is the area stated in the question.
Thus, the value of "h" is verified through mental math.
So-called simplifying, really means, "rationalizing the denominator", which is another way of saying, "getting rid of that pesky radical in the bottom"