Question

Find the Value of the letter in the following questions. Give your answers to 3 s.f.

Answer 1

Answer:

i = 75.7°

h = 48.2°

Step-by-step explanation:

==>To find i, use the sine rule for finding angles: sin(A)/a = sin(B)/b

Where,

a = 7.2cm

sin(A) = i

b = 6.5cm

sin(B) = sin(61) = 0.8746

Thus:

sin(A)/7.2 = 0.8746/6.5

Multiply both sides by 7.2

sin(A) = (0.8746*7.2)/6.5

sin(A) = 0.969 (3 s.f)

A = i° = sin^-1(0.969) = 75.7 (3 s.f)

==>To find h, use the Cosine rule for angles:

Cos(C) = (a²+b²-c²)/2ab

cos(C) = h°, a = 4, b = 4.5, c = 3.5

a² = 16

b² = 20.25

c² = 12.25

cos(C) = (16+20.25-12.25)/(2*4*4.5)

cos(C) = 24/36

cos(C) = 0.667 (3 s.f)

C = h° = cos^-1(0.667) = 48.2° (3 s.f)