Question

The perimeter of a triangle is 29 millimeters. The length of the first side

is twice the length of the second side. The length of the third side is
5 more than the length of the second side. Find the side lengths of the
triangle. Then classify the triangle by its side lengths.

Answer 1

7.25, 3.625, 18.125

Scalene triangle

Explanation:

Turn the lengths into a ratio:

First side twice as long as second side

Third side 5 times as long as second side

First side : Second side : Third side = 2 : 1 : 5

2 + 1 + 5 = 8

29 / 8 = 3.625

Multiply the ratio by 3.625:

3.625 x 2 = 7.25

3.625 x 1 = 3.625

3.625 x 5 = 18.125

The sides so not follow Pythagoras's theorem a² + b² = c² (c being the largest side, so it is not a right angled triangle so it is a scalene triangle