मराठी

Determine the Measure of Each of the Equal Angles of a Right-angled Isosceles Triangle.

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प्रश्न

Determine the measure of each of the equal angles of a right-angled isosceles triangle.

ABC is a right-angled triangle in which ∠A = 90° and AB = AC. Find ∠B and ∠C.

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उत्तर

Given to determine the measure of each of the equal angles of right– angled isosceles triangle

Consider on a right – angled isosceles triangle ABC such that

∠A = 90° and AB = AC

Since, AB = AC ⇒ ∠C = ∠B   ……….(1)

[Angles opposite to equal sides are equal] Now,

Sum of angles in a triangle = 180°

∠A + ∠B +∠C = 180°

⇒  90° + ∠B + ∠B = 180°       [ ∴∠A = 90° and ∠B = ∠C ]  

⇒ 2∠B = 90°

⇒ ∠B = 45°⇒  ∠C = 45°

∴ ∠B =∠C = 45°

Hence, the measure of each of the equal angles of a right-angled isosceles triangle is 45°.

 

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पाठ 12: Congruent Triangles - Exercise 12.1 [पृष्ठ १६]

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आर.डी. शर्मा Mathematics [English] Class 9
पाठ 12 Congruent Triangles
Exercise 12.1 | Q 11 | पृष्ठ १६

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