Answer:
the base of the triangle is 8 cm
Step-by-step explanation:
Area of a triangle(A) is given by:
....[1]
where b is the base and h is the height of the triangle respectively.
As per the statement:
the height of a triangle is 7 cm longer than its base.
⇒
It is also given that: The area of the triangle is 60 cm²
⇒
cm²
Substitute the given values in [1] we have;

Multiply both sides by 2 we have;

or

⇒
Now factorize this equations:

⇒
⇒
By zero product property we have;
b-8 = 0 and b+15 = 0
⇒b = 8 and b = -15
Since, the base of the triangle cannot be in negative.
⇒b = 8 cm
Therefore, the base of the triangle is 8 cm