Question -
Answer -
We know that π rad = 180° ⇒ 1 rad = 180°/ π
(i) 9π/5
[(180/π) ×(9π/5)] o
Substituting the value of π = 22/7
[180/22 × 7× 9 × 22/(7×5)]
(36 × 9) °
324°
∴Degree measure of 9π/5 is 324°
(ii) -5π/6
[(180/π) ×(-5π/6)] o
Substituting the value of π = 22/7
[180/22 × 7× -5 × 22/(7×6) ]
(30 × -5) °
– (150) °
∴Degree measure of -5π/6 is -150°
(iii) (18π/5)
[(180/π) ×(18π/5)] o
Substituting the value of π = 22/7
[180/22 × 7× 18 × 22/(7×5)]
(36 × 18) °
648°
∴Degree measure of 18π/5 is 648°
(iv) (-3) c
[(180/π) ×(-3)] o
Substituting thevalue of π = 22/7
[180/22 × 7× -3] o
(-3780/22) o
(-171 18/22) o
(-171 o (18/22 × 60)’)
(-171o (49 1/11)’)
(-171o 49′ (1/11 × 60)’)
– (171° 49′ 5.45”)
≈ – (171° 49′ 5”)
∴Degree measure of (-3) c is -171° 49′ 5”
(v) 11c
(180/ π × 11) o
Substituting the value of π = 22/7
(180/22 × 7 × 11) o
(90 × 7) °
630°
∴Degree measure of 11c is 630°
(vi) 1c
(180/ π × 1) o
Substituting thevalue of π = 22/7
(180/22 × 7 × 1) o
(1260/22) o
(57 3/11) o
(57o (3/11 × 60)’)
(57o (16 4/11)’)
(57o 16′ (4/11 × 60)’)
(57o 16′ 21.81”)
≈ (57o 16′ 21”)
∴Degree measure of 1c is 57o 16′ 21”