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A landscaper is designing a flower garden in the shape of a trapezoid. She wants the shorter base to be 3 yards greater than the height, and the longer base to be 7 yards greater than the height. She wants the area to be 225 square yards. The situation is modeled by the equation . Use the Quadratic Formula to find the height that will give the desired area. Round to the nearest hundredth of a yard.

2 Answers

7 votes
The equation is to be given, judging by the tone problem given but apparently it's not given. The equation can be derived from the problem. The area of a trapezoid is given by the equation
A = ((a+b))/(2) h. Also, given that a, is the longer side, then a = h+7 and b (shorter side) = h+3 and h is the height. the equation is then
A = ((h+3)(h+7))/(2)h = 225. Solving this quadratic equation, h is 4.84.
User Phindmarsh
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8.0k points
7 votes

Let

x--------> shorter base in yards

y--------> the longer base in yards

z-------> the height in yards

we know that

the area of the flower garden in the shape of a tra-pezoid is


A=(1)/(2) (x+y)z


A=225\ yd^(2)

so


225=(1)/(2) (x+y)z --------> equation
1


x=z+3 --------> equation
2


y=z+7 --------> equation
3

Substitute equation
2 and equation
3 in equation
1


225=(1)/(2) ((z+3)+(z+7))z


225=(1)/(2) ((z+3)+(z+7))z\\ \\450=[2z+10]z\\ \\2z^(2)+10z-450=0

Solve the quadratic equation for z

using a graphing tool

see the attached figure

the solution is


z=12.71\ yd

therefore

the answer is

the height of the flower garden in the shape of a tra-pezoid is
12.71\ yd


A landscaper is designing a flower garden in the shape of a trapezoid. She wants the-example-1
User Ducktyped
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8.4k points