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# A clock has a minute hand 16 cm long and an hour hand 11 cm long. Find the distance between the outer tips of the hand at 2:25 o'clock.

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A clock has a minute hand 16 cm long and an hour hand 11 cm long. Find the distance between the outer tips of the hand at 2:25 o'clock.

Jun 23, 2015

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A clock has a minute hand 16 cm long and an hour hand 11 cm long. Find the distance between the outer tips of the hand at 2:25 o'clock.

The angle between the clock's hands at 2:25 is 77.5o.

short hand s = 11cm,  long hand l = 16cm,     d = ? (d is the distance between the outer tips of the hands)

We can use cosine rule:     d2 = s2 + l2 - 2sl cos(A)

d2 = 112 + 162 - 2*11*16*cos 77.5o

d = 17.344cm

Jun 24, 2015

#1
+1068
+8

A clock has a minute hand 16 cm long and an hour hand 11 cm long. Find the distance between the outer tips of the hand at 2:25 o'clock.

The angle between the clock's hands at 2:25 is 77.5o.

short hand s = 11cm,  long hand l = 16cm,     d = ? (d is the distance between the outer tips of the hands)

We can use cosine rule:     d2 = s2 + l2 - 2sl cos(A)

d2 = 112 + 162 - 2*11*16*cos 77.5o

d = 17.344cm

civonamzuk Jun 24, 2015