Question

The perimeter of the scalene triangle is 54.6 cm.Which equation can be used to find the value of b if side a measures 8.7 cm?

a. 8.7 + b = 54.6
b. 17.4 + b = 54.6
c. 26.1 + b = 54.6
d. 34.8 + b = 54.6

Answer 1

Hi!
The answer would be B: 17.4+b=54.6.

The reason we know this is because in a scalene triangle, two sides are congruent with one irregular side. Assuming that one of the two congruent sides measures 8.7cm, we know that the triangle has 2 8.7cm sides, sides, hence the 17.4. If we add the unknown side, or b, we should get 54.6.

Answer 2

The answer is option B: 17.4+b=54.6

Explanation:

A scalene triangle is a triangle whose 2 sides are equal and one side is different. Here, we have been given that one side is 8.7 cm. We can assume that the other side is also 8.7 cm and we have to find the third side. Let that side be = b

So, the perimeter is given as :
`P=a+b+c`

We have a and c as 8.7 and p=54.6

So, equation becomes:

`54.6=8.7+b+8.7`

`54.6=17.4+b`

Or,
`17.4+b=54.6`

Hence, option B is the right answer.