9514 1404 393
Answer:
base: 12 in
altitude: 7 in
Step-by-step explanation:
The formula for the area of a triangle is ...
A = 1/2bh
Filling in the given information, we have ...
42 = 1/2(b)(b -5)
b^2 -5b -84 = 0 . . . . multiply by 2, put in standard form
(b -12)(b +7) = 0 . . . . factor
The only positive solution is b = 12
The base is 12 inches; the altitude is 7 inches.
