At the bank of a river, by measurement, a = 18 ft. b = 30 ft. c = 24 ft. d = 14 ft. how long is x?
11.2 ft.
18.7 ft.
40.0 ft.

Since you did not give the picture of the problems so it is difficult to solve the problem. but i think this problem is about similar triangles, similar triangle are triangles that have corresponding angles are congruent and their sides are in proportion.
( x / 24) = 30 /18
x = 24 ( 30 / 18 )
x = 40 ft

Where are the following equations?

Iwould like to think so. what’s the question you need with?