मराठी

In Triangle Abc, ∠B = 90° and Tan a = 0.75 If Ac = 30 Cm Find the Lengths of Ab and Bc - Mathematics

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प्रश्न

In triangle ABC, ∠B = 90° and tan A = 0.75. If AC = 30 cm, find the lengths of AB and BC.

बेरीज

उत्तर

Consider the figure :

tan A = `(75)/(100) = (3)/(4)`

i.e.`"perpendicular"/"base" = "BC"/"AB" = (3)/(4)`

Therefore if length of base = 4x, length of perpendicular = 3x

Since
BC2 + AB2 = AC2     ...[ Using Pythagoras Theorem ]

(3x)2 + (4x)2 = AC2

AC2 = 9x2 + 16x2 = 25x2

∴ Ac = 5x

Now
Ac = 30

5x = 30

x = 6

Therefore
AB = 4x

= 4 x 6

= 24 cm

And
Bc = 3x

= 3 x 6

= 18 cm

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पाठ 22: Trigonometrical Ratios [Sine, Consine, Tangent of an Angle and their Reciprocals] - Exercise 22 (B) [पृष्ठ २८७]

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सेलिना Concise Mathematics [English] Class 9 ICSE
पाठ 22 Trigonometrical Ratios [Sine, Consine, Tangent of an Angle and their Reciprocals]
Exercise 22 (B) | Q 17 | पृष्ठ २८७
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