I hope this answers your question !
Answer:
Step-by-step explanation:
Similar figures have the same shape but the same size.
Moving from left to right:
The first figure is similar because the ratio is 6:14 which is the same as the figure 3:7.
The second figure is not similar because of shape
The third figure is is not similar because the ratio is 6:12 which is not the same as the figure 3:7
The fourth figure is similar because it is rotated
The fifth figure is not similar because of shape
The sixth figure is not similar because of the ratio of 2:3.5 which is not the same as the figure's ratio of 3:7
You found CD from the Pythagorean theorem to be ...
... CD = √(5² -2²) = √21
Since triangle ADC ~ triangle ACB, the ratios of corresponding sides are the same:
... AC/AD = AB/AC
... AB = AC²/AD
... AB = 5²/2 = 12.5 . . . . . . . the base of the overall triangle
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Then the area (A) is ...
... A = (1/2)bh
... A = (1/2)(12.5)(√21) ≈ 28.64 square units
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As you see here, the altitude of a right triangle divides it into three similar triangles. From smallest to largest, they are ...
... ADC ~ CDB ~ ACB
You can figure this using AAA similarity, since the smallest and largest triangles listed above share an acute angle vertex (∠A). That, together with the right angle, means all angles are congruent. After that, then you know ∠ACD ≅ ∠CBD, so you can show the middle sized triangle is similar to the other two.
