Respuesta :
the formula for the area of a triangle is 1/2*base*height so setting a=18 you can set up the equation as 18=1/2*b*h which gives 18=1/2*(c-1)*6c. simplifying gives 18=3c(c-1). setting the equation to 0 gives a quadratic which is
3c^2-3c-18=0 which gives c= 3 or -2 since -2 doesnt make sense we can assume c=3 so filling the equation with c=3 gives 18=1/2*(6*3)*(3-1) which gives 18=1/2(18)(2) you see 1/2*2 cancels and you are left with 18=18 which is correct so c=3 and height =18
3c^2-3c-18=0 which gives c= 3 or -2 since -2 doesnt make sense we can assume c=3 so filling the equation with c=3 gives 18=1/2*(6*3)*(3-1) which gives 18=1/2(18)(2) you see 1/2*2 cancels and you are left with 18=18 which is correct so c=3 and height =18
The equation Brian can use is: 1/2(c - 1)(6c) = 18 or 6c² - 6c - 36 = 0
The height of the triangles is 18 m.
What is the Area of a Triangle?
If h = height of a triangle, and b is the base of the triangle, then the area of a triangle is expressed as: 1/2(b)(h).
Given:
h = 6c m
b = (c - 1) m
Area of triangle = 18 sq. m
The equation that Brian can use would be:
1/2(c - 1)(6c) = 18
Find the value of c:
(c - 1)(6c) = 36
6c² - 6c = 36
6c² - 6c - 36 = 0
Factoring and setting each factor equal to zero, we will have:
c = 3, or c = -2
Lets use the positive value of c. Thus:
height of the triangle = 6c
Substitute c = 3
height of the triangle = 6(3) = 18 m.
Thus, the equation Brian can use is: 1/2(c - 1)(6c) = 18 or 6c² - 6c - 36 = 0
The height of the triangles is 18 m.
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