Question

Quadrilateral ABCD is similiar to quadrilateral EFGH. The lengths of the three longest sides in quadrilateral ABCD are 60 feet, 40 feet, and 30 feet long. If the two shortest sides of quadrilateral EFGH are 6 feet long and 12 feet long, how long is the 2nd longest side on quadrilateral EFGH?

A. 24 feet
B. 20 feet
C. 16 feet
D. 18 feet​

Answer 1

C) y = 16 feet

Explanation:

the corresponding sides in ABCD are equal to their corresponding sides by EFGH multiplied by something

all values are in feet

let x represent the unknown side in ABCD

ABCD lengths in order: x, 30 , 40 , 60

let a and b represent the unknown sides in EFGH

EFGH lengths in order: 6, 12, a, b

thus, 30 corresponds to 12 as they are both the second shortest sides

corresponding side in EFGH * something = corresponding side in ABCD

12 * something = 30

let something be r

12 * r = 30

divide both sides by 12 to isolate r

r = 30/12

thus, to get a side in ABCD, we multiply the corresponding side in EFGH by 30/12

we want to find the second longest side in EFGH. the corresponding side to that in ABCD is 40, as 40 is the second longest side in ABCD

let the second longest side in EFGH = y

y * 30/12 = 40

multiply both sides by 12/30 to isolate y

40 * 12 / 30 = y = 16

y = 16 feet