Question

two poles 18m and 13 m high,stand upright in a playground. If their feel are 12m apart,find the distance between their tops.

Answer 1

Given data : Two poles 18 m and 13 m high stand upright in a playground. They are 12 meters apart,

To find : find the distance between their tops.

Solution : A/C to figure;

Let, AD and BC are two poles and they are 12 m apart

Hence,

• AD = 18 m
• BC = 13 m
• CD = 12 m

Poles stans upright in a ground. Hence angle between poles and ground is 90⁰.

Construction : From the vertex of pole BC, draw BE parallel to CD. {BE perpendicular to AD} where EB = CD.

Hence, ED = BC

Length of ED = BC = 13 m ----{1}

and

length of EB = CD = 12 m ----{2}

Now, we have to find out the length of AE

Here, we know AD = AE + ED

➜ AE + ED = AD

from {1}

➜ AE + 13 = 18

➜ AE = 18 - 13

➜ AE = 5 m

Now, we have to find out, the distance between their tops { BA = ? } so we use Pythagoras theorem;

• AB = Hypotenuse
• AE = First side
• BE = Second side

➜ (AB)² = (AE)² + (BE)²

➜ (AB)² = 5² + 12²

➜ (AB)² = 25 + 144

➜ (AB)² = 169

➜ AB = √169

➜ AB = 13 m

Answer : Hence, the distance between tops of the two poles is 13 m.