Question

The perimeter of the scalene triangle is 54.6 cm.

A scalene triangle where all sides are different lengths. The base of the triangle, labeled 3 a, is three times that of the shortest side, a. The other side is labeled b.

Which equation can be used to find the value of b if side a measures 8.7 cm?

8.7 plus b equals 54.6
17.4 plus b equals 54.6
26.1 plus b equals 54.6
34.8 plus b equals 54.6

Answer 1

Perimeter = a + 3a + b = 4a + b. With a = 8.7, 4a = 34.8, so the equation is

34.8 + b = 54.6.

(Then b = 54.6 − 34.8 = 19.8 cm.)