Question

the perimeter of a triangle is 29cm. the three sides lengths (all measured in cm) of the triangle are 8, 12 and x. Write and solve an equation to find x.​

Answer 1

9 cm

Explanation:

The perimeter of a polygon is the sum of the lengths of all the sides of the polygon.

If a polygon is a triangle, and its 3 sides have length a, b, and c, then the perimeter is the sum of a, b,, and c.

perimeter = a + b + c

Here, the perimeter = 29 cm

The lengths of the sides are a = 8 cm, b = 12 cm, c = x.

8 + 12 + x = 29

x + 20 = 29

x = 9

Answer: 9 cm

Answer 2

Explanation:

We have 8 + 12 + x = 29.

Solving, we get x + 20 = 29, x = 9.