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In a DeltaABC, a = 2, b = 3 and sinA = 2...

In a `DeltaABC`, a = 2, b = 3 and sinA = `2/3`, find `angleB`.

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To solve the problem, we will use the Law of Sines, which states that the ratio of the sine of an angle to the length of its opposite side is constant for all angles in a triangle. ### Step-by-Step Solution: 1. **Identify the given values**: - Side \( a = 2 \) - Side \( b = 3 \) - \( \sin A = \frac{2}{3} \) 2. **Use the Law of Sines**: According to the Law of Sines: \[ \frac{\sin A}{a} = \frac{\sin B}{b} \] Substituting the known values: \[ \frac{\frac{2}{3}}{2} = \frac{\sin B}{3} \] 3. **Simplify the left side**: \[ \frac{2}{3} \div 2 = \frac{2}{3} \times \frac{1}{2} = \frac{2}{6} = \frac{1}{3} \] So, we have: \[ \frac{1}{3} = \frac{\sin B}{3} \] 4. **Cross-multiply to solve for \( \sin B \)**: \[ 1 \cdot 3 = \sin B \cdot 3 \] Thus: \[ \sin B = 1 \] 5. **Find angle \( B \)**: The sine of an angle is equal to 1 when the angle is \( 90^\circ \): \[ B = 90^\circ \] ### Final Answer: Angle \( B \) is \( 90^\circ \).
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ICSE-PROPERTIES OF TRIANGLE-EXERCISE 7
  1. In a DeltaABC, a = 2, b = 3 and sinA = 2/3, find angleB.

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  2. In DeltaABC, if a = 2, b = 3, c = 4, prove that cosA=7/8.

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  3. In DeltaABC, if the sides are 7, 4sqrt(3) and sqrt(13) cm, prove tha...

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  4. In DeltaABC, if a = 9, b = 8, c = 4, prove that 6cosC=4+3cosB.

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  5. In DeltaABC, The sines of the angles of a triangle are in the ratio ...

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  6. In DeltaABC, If the two angles of a triangle are 30^(@) and 45^(@) a...

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  7. In DeltaABC, If in a DeltaABC, a = 6, b = 3 and cos(A-B)=4/5, find i...

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  8. In DeltaABC, In a triangle ABC, angleC=60^(@) and angleA=75^(@). If ...

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  9. In any DeltaABC, prove that (sinA)/(sin(A+B))=a/c

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  10. In any DeltaABC, prove that (a-b)/(a+b)=(tan""1/2(A-B))/(tan""1/2(A+...

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  11. In any DeltaABC, prove that ac""cosB-bc""cosA=a^(2)-b^(2)

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  12. In any DeltaABC, prove that (sin(A-B))/(sin(A+B))=(a^(2)-b^(2))/c^(2...

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  13. In any DeltaABC, prove that a(sinB-sinC)+b(sinC-sinA)+c(sinA-sinB)=0

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  14. In any DeltaABC, prove that acos(A+B+C)-bcos(B+A)-c""cos(A+C)=0

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  15. In any DeltaABC, prove that a(cosC-cosB)=2(b-c)cos^(2)""1/2A

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  16. In any DeltaABC, prove that asin""1/2(B-C)=(b-c)cos""1/2A

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  17. In any DeltaABC, prove that asin(A/2+B)=(b+c)sin""A/2

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  18. In any DeltaABC, prove that c^(2)=(a-b)^(2)cos^(2)""1/2C+(a+b)^(2)si...

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  19. In any DeltaABC, prove that asin(B-C)+bsin(C-A)+csin(A-B)=0

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  20. In any DeltaABC, prove that (cos2A)/a^(2)-(cos2B)/b^(2)=1/a^(2)-1/b^...

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  21. In any DeltaABC, prove that (1+cos(A-B)cosC)/(1+cos(A-C)cosB)=(a^(2)...

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