Question

Which equation would best help solve the following problem? The height of a triangle is 5 m less than its base. The area of the triangle is 42 m² What is the length of the base?​

Answer 1

`\boxed{\displaystyle 42=(1)/(2)x(x-5)}`

The second choice is correct

Explanation:

Area of a Triangle

Given a triangle of base B and height H, the area is calculated by the formula:

`\displaystyle A=(1)/(2)BH`

Let's call x=base of a triangle

Since the height of the triangle is 5 m less than the base:

x - 5 = height of the triangle.

Thus, the area is

`\displaystyle A=(1)/(2)x(x-5)`

The value of the area is given as A=42 square meters, thus:

`\boxed{\displaystyle 42=(1)/(2)x(x-5)}`

The second choice is correct