In the given angle abc is a right angled triangle at c and ad _! Ab . If angle b =40 then find angle bac
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Right angled triangle at B altitude is BD AD =3 DC = 9 find AB?
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Girija Warrier, Passionate about Maths & Music...
Answered Aug 22, 2017 · Author has 1.9kanswers and 1.6m answer views

Angle B = 90° ( given)
=> <1 + <2 = 90° ( as shown in the figure)……(1)
BD is perpendicular to AC ( given)
=> <1 + <DCB = 90° …….(2)
=> < DCB = <2 ………….by (1) & (2)
& < BAD = <1
So, Triangle BCD ~ triangle ABD ( by AAA similarity theorem)
=> BC/AB = CD/BD = BD/AD ( corresponding sides of similar triangles)
=> BC/AB = 9/BD = BD/3
= BD² = 27
=> BD = 3√3
AB² = AD² + BD²
=> AB² = 3² + (3√3)²
= AB² = 9 + 27 = 36
=> AB = 6
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Girija Warrier, Passionate about Maths & Music...
Answered Aug 22, 2017 · Author has 1.9kanswers and 1.6m answer views

Angle B = 90° ( given)
=> <1 + <2 = 90° ( as shown in the figure)……(1)
BD is perpendicular to AC ( given)
=> <1 + <DCB = 90° …….(2)
=> < DCB = <2 ………….by (1) & (2)
& < BAD = <1
So, Triangle BCD ~ triangle ABD ( by AAA similarity theorem)
=> BC/AB = CD/BD = BD/AD ( corresponding sides of similar triangles)
=> BC/AB = 9/BD = BD/3
= BD² = 27
=> BD = 3√3
AB² = AD² + BD²
=> AB² = 3² + (3√3)²
= AB² = 9 + 27 = 36
=> AB = 6
2.7k Views · View 1 Upvoter · Answer requested by
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