Question

HELP!! joels apartment building is 42 ft tall and casts a shadow of 20ft. If Joel is 6 ft tall, how long is his shadow

Answer 1

Step-by-step explanation:

an object and its shadow create a right-angled triangle.

2 objects and their shadows create 2 similar right-angled triangles.

that means the angles are the same, and the side lengths of one triangle all correlate with the corresponding side lengths of the other triangle via the same factor.

so,

42 × f = 6

f = 6/42 = 1/7

the length of Joel's shadow is then

20 × f = 20 × 1/7 = 2.857142857... ft