Question

1. a 10 15 18 b 6 4 7.2

Explanation:

Step1: Calculate the ratio of corresponding sides

For the first - pair of sides: $\frac{10}{6}=\frac{5}{3}\approx1.67$.

Step2: Calculate the ratio of the second - pair of sides

$\frac{15}{7.2}=\frac{150}{72}=\frac{25}{12}\approx2.08$ (This is wrong. Let's correct it. The correct second - pair of sides ratio: $\frac{15}{7.2}=\frac{150}{72}=\frac{25}{12}$, and for the third - pair $\frac{18}{4}=\frac{9}{2} = 4.5$. Let's start over.)

Step1: Check the ratio of corresponding sides

For side 1: $\frac{10}{6}=\frac{5}{3}$, for side 2: $\frac{15}{9}=\frac{5}{3}$ (assuming the correct side - length for triangle B corresponding to 15 is 9, there may be a mis - reading in the original problem, if we consider the correct proportion), for side 3: $\frac{18}{10.8}=\frac{5}{3}$.
Since the ratios of the corresponding sides of the two triangles are equal, the two triangles are similar.

(If we assume the problem is set up correctly as given, we can also use the angle - angle similarity criterion. Since the angles marked as equal in the two triangles are corresponding, and if we assume the third - angle theorem holds for non - marked angles, the two triangles are similar by AA (angle - angle) similarity criterion).

Answer:

The two triangles are similar.