Question

a cable wire of length 61m is attached to the top of a building from the bottom of a pole fixed at a distance of 11 m from the bottom of the building. find the height of the building

Answer 1

• Let the top of the building be point A and the bottom of the building be B and the pole be C

• given: AC =length of the wire =61 m, and BC =distance from the bottom of the building to the pole =11 m
• to find: the height of the building =AB
• Since AB is the building it is  perpendicular to the ground or the base that is BC
• therefore, AB is ⊥ to BC
• now by Pythagoras theorem
• AC²= AB² + BC²       ----- eq (1)
• from (1), we get AB²=AC² - BC²

                                         =(61)² - (11)²

                                         =3721 - 121

                                         =3600

                                  AB²=3600

                                  AB =60

• Therefore, the height of the building is 60 m