Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar. is parallel to , and is perpendicular to . The number of 90° angles formed by the intersections of and the two parallel lines and is .

The question is not complete, below is a complete question with the accompanying diagram:

Instructions: Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.

AB is parallel to CD, and EF is perpendicular to AB

The number of 90° angles formed by the intersections of Ef and the two parallel lines AB and CD is ____

The number of 90° angle formed = 8 angles

Step-by-step explanation:

From the question and attached diagram, the following information is given:

AB is parallel to CD

EF is perpendicular to AB

Required: number of 90° angles formed by the intersection of the perpendicular line and the parallel lines.

Note, the angle formed between a line and a perpendicular line = 90°

From the diagram:

Number of 90° angle formed by intersection of perpendicular line EF and line AB = ∠1, ∠2, ∠3 and ∠4 = 4 angles

Number of 90° angle formed by intersection of perpendicular line EF and line  CD = ∠5, ∠6, ∠7 and ∠8 = 4 angles

Total 90° angles formed by perpendicular line with lines = ∠1, ∠2, ∠3, ∠4, ∠5, ∠6, ∠7, and ∠8 = 8 angles

geometry: triangles

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answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

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