The height of a triangle is 5 less its base. The area of the triangle is 42 square inches. Create an equation that represents this situation. Use the concept of finding roots/zeros to find the base and height of the triangle.
Area of a triangle = 1/2 base x height b = b h = b-5 area = 42 in^2 (given)
42 = 1/2 b (b-5)
84 = b^2-5b
b^2-5b - 84 = 0 factor (or use quadratic formula)
(b+7)(b-12)= 0 so b can = 12 or -7 toss out -7 because you can't have a negative length
so b = 12
h = b-5 = 12-5 = 7
Check: Area = 1/2 b h = 1/2 12 7 = 42 Correct !
Hi!
So what you need to know for this, is the formula for the area of a triangle which is 1/2 x base x height
The area of the triangle is given to you.
So 42 = 1/2 x b x 5-b
Then after that, you can probably use Algebra to find out the answer. This would require the use of quadratic roots and zeroes, like you said. So you would find answers that look like this (x-2)=0- and (x+2)=0. I'm not saying this is exactly what you'll get, but something along the lines of that.
Then you just solve! :) Hope this helps... I tried L:
Area of a triangle = 1/2 base x height b = b h = b-5 area = 42 in^2 (given)
42 = 1/2 b (b-5)
84 = b^2-5b
b^2-5b - 84 = 0 factor (or use quadratic formula)
(b+7)(b-12)= 0 so b can = 12 or -7 toss out -7 because you can't have a negative length
so b = 12
h = b-5 = 12-5 = 7
Check: Area = 1/2 b h = 1/2 12 7 = 42 Correct !