Question

describe how to use ratios to determine whether two shapes are similar. confirm that the measures of the corresponding angles are (select) then find ratios of side lengths to determine if the corresponding side lengths are (select).

Explanation:

Step1: Recall Similar Shapes Definition

For two shapes to be similar, their corresponding angles must be equal (congruent), and their corresponding side lengths must be in proportion (have equal ratios).

Step2: Analyze First Select

The first blank is about corresponding angles. In similar figures, corresponding angles are equal (congruent). So we fill "equal (or congruent)".

Step3: Analyze Second Select

The second blank is about corresponding side lengths. For similarity, the ratios of corresponding side lengths must be equal (i.e., the sides are proportional). So we fill "proportional (or have equal ratios)".

Answer:

First select: equal (or congruent)
Second select: proportional (or have equal ratios)