Find the largest scale size to measure accurately, the three equilateral triangles with sides measuring 129 cm, 172 cm and 215 cm. (In cm)

Given:

Side lengths of equilateral triangles: 129 cm, 172 cm, and 215 cm.

Concept Used:

To find the largest scale size to measure accurately, we need to find the greatest common divisor (GCD) of the side lengths.

Calculation:

GCD of 129, 172 and 215.

129 = 3 × 43

172 = 2 × 86 = 2 × 2 × 43

215 = 5 × 43

GCD = 43

The largest scale size to measure accurately the three equilateral triangles is 43 cm.