Question

finding the height of flag pole using the criterion of similarity of triangle
it's urgent can any one give me a satisfy answer ​

Answer 1

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\tt{\therefore{Height\:of\:flag=15\:feet}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

$\green{\underline \bold{Given : }} \\ \tt: \implies \triangle ABC \sim \triangle D E F \\ \\ \tt: \implies BC = 20 \: feet \\ \\ \tt: \implies DE = 3 \: feet \\ \\ \tt: \implies EF= 4 \: feet \\ \\ \red{\underline \bold{To \: Find : }} \\ \tt: \implies AB =?$

• According to given question :

$\bold{As \: we \: know \: that} \\ \tt: \implies \triangle ABC \sim \triangle \: D E F \\ \\ \tt: \implies \frac{AB}{BC} = \frac{DE}{EF} \\ \\ \tt: \implies \frac{h}{20} = \frac{3}{4} \\ \\ \tt: \implies 4h = 60 \\ \\ \tt: \implies h = \frac{60}{4} \\ \\ \green{\tt: \implies h = 15 \: feet} \\ \\ \green{\tt \therefore Height \: of \: flag \: is \: 15 \: feet}$

Answer 2

Assume that the first triangle is ABC and second triangle is PQR.

In triangle ABC

sinø = P/B

As the triangle is making an angle of 90°. So,

→ sin 90° = P/B

→ 1 = h/20 ......................(1)

Similarly, In triangle PQR

→ sin 90° = P/B

→ 1 = 3/4 .......................(2)

On comparing equation (1) & (2) we get,

→ h/20 = 3/4

Cross multiply it

→ 4h = 3(20)

→ h = 3(5)

→ h = 15

Hence, the height of the flag is 15 feet.