The height of a triangle is 4 inches greater than twice its base. The area of the triangle is no more than 168 in[tex]\(^2\)[/tex]. Which inequality can be used to find the possible lengths, [tex]\(x\)[/tex], of the base of the triangle?

A. [tex]\(x(x+2) \geq 168\)[/tex]

B. [tex]\(x(x+2) \leq 168\)[/tex]

C. [tex]\(\frac{1}{2} x(x+4) \leq 168\)[/tex]

D. [tex]\(\frac{1}{2} x(x+4) \geq 168\)[/tex]



Answer :

Let's find the correct inequality to express the possible lengths, [tex]\( x \)[/tex], of the base of the triangle given the conditions provided.

1. Define the Variables:
- Let [tex]\( x \)[/tex] be the base of the triangle (in inches).
- The height of the triangle is 4 inches greater than twice its base, which can be expressed as [tex]\( 2x + 4 \)[/tex].

2. Recall the Formula for the Area of a Triangle:
- The area [tex]\( A \)[/tex] of a triangle is given by [tex]\( A = \frac{1}{2} \times \text{base} \times \text{height} \)[/tex].

3. Substitute the Given Values into the Area Formula:
- Substitute [tex]\( x \)[/tex] for the base and [tex]\( 2x + 4 \)[/tex] for the height:
[tex]\[ A = \frac{1}{2} \times x \times (2x + 4) \][/tex]

4. Set up the Inequality Based on the Given Condition:
- It’s given that the area of the triangle is no more than 168 square inches. Thus, we have the inequality:
[tex]\[ \frac{1}{2} \times x \times (2x + 4) \leq 168 \][/tex]

5. Simplify the Inequality:
- First, simplify the expression inside the inequality:
[tex]\[ \frac{1}{2} \times x \times (2x + 4) \leq 168 \][/tex]
- Simplify the multiplication:
[tex]\[ \frac{1}{2} \times (2x^2 + 4x) \leq 168 \][/tex]
- Distribute the [tex]\(\frac{1}{2}\)[/tex]:
[tex]\[ x^2 + 2x \leq 168 \][/tex]

6. Express the Final Inequality:
- The resulting inequality is:
[tex]\[ x^2 + 2x \leq 168 \][/tex]
- This can be rewritten as:
[tex]\[ x(x + 2) \leq 168 \][/tex]

Thus, the inequality that can be used to find the possible lengths [tex]\( x \)[/tex] of the base of the triangle is:
[tex]\[ x(x + 2) \leq 168 \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{x(x+2) \leq 168} \][/tex]