Question

17. The length of a shadow of 5 m high pole at a certain time of a day is 7.5 m. What will be the height of another
pole whose shadow at the same time is 90 m long?​

Answer 1

Step-by-step explanation:

Height of pole=AB=6 m

Length of shadow of pole =BC=4 m

Length of shadow of tower=EF=28 m

In △ABC and △DEF

∠B=∠E=90∘ both 90∘ as both are vertical to ground

∠C=∠F  (same elevation in both the cases as both shadows are cast at the same time)

∴△ABC∼△DEF by AA similarity criterion

We know that if two triangles are similar, ratio of their sides are in proportion

So,DEAB=EFBC

⇒DE6=284

⇒DE=6×7=42 m

Hence the height of the tower is 42 m