Need help! Pendulum of 45cm long swings through its vertical angle of 30º?

Question

What is the increase in altitude that the bob travelled?

Answer 1

h
= 45 - 45cos30
= 45(1 - cos30)
= 45(1 - √3/2)
≈ 6.03 cm

Answer 2

WHEN ANGLE IS 30°:-
vertical component = 45.cos 30°
vertical component = 45.√3 / 2
Let increase in altitude = x cm
Now 45.√3/2 + x = 45
x = 45 - 45.√3 / 2
x = 45.(1 - √3/2)
x = 6.03 cm
Increase in altitude = 6.03 cm

Answer 3

Draw a triangle.

Do the math.