Trigonometry: missing sides, mixed

The Maths Habit Code breaker to print

Last lesson. Find x to 1 decimal place.

a

x = 7.6 cm

b

x = 10.6 cm

c

x = 6.1 cm

A right-angled triangle
has a 44° angle and a 10 cm side.
Sketch it. Is there only one
triangle it could be?

Which ratio? SOH, CAH or TOA. Just decide.

a

SOH

b

TOA

c

CAH

d

SOH

e

CAH

f

TOA

Finding a missing side

1. Labelonly the two sides you use: O, A or H from the angle.
2. PickSOH, CAH or TOA: the one with both your letters.
3. Writethe ratio with the numbers in.
4. RearrangeMake the unknown the subject of the formula.
5. CalculateUse your calculator. Round as asked.

Label the two sides. Pick SOH, CAH or TOA.

TOA

tan 38° = x8.5

x = 8.5 × tan 38°

x = 6.6 cm

CAH

cos 56° = 7x

x = 7 ÷ cos 56°

x = 12.5 cm

Label the two sides. Pick SOH, CAH or TOA.

TOA

tan 38° = x8.5

x = 8.5 × tan 38°

x = 6.6 cm

SOH

sin 46° = x11

x = 11 × sin 46°

x = 7.9 cm

Label the two sides. Pick SOH, CAH or TOA.

TOA

tan 38° = x8.5

x = 8.5 × tan 38°

x = 6.6 cm

TOA

tan 35° = 6x

x = 6 ÷ tan 35°

x = 8.6 cm

Label the two sides. Pick SOH, CAH or TOA.

TOA

tan 38° = x8.5

x = 8.5 × tan 38°

x = 6.6 cm

CAH

cos 50° = x14

x = 14 × cos 50°

x = 9.0 cm

Label the two sides. Pick SOH, CAH or TOA.

TOA

tan 38° = x8.5

x = 8.5 × tan 38°

x = 6.6 cm

SOH

sin 27° = 4.5x

x = 4.5 ÷ sin 27°

x = 9.9 cm

Find x to 1 decimal place.

a

x = 14.0 cm

b

x = 5.6 cm

c

x = 10.4 cm

d

x = 6.4 cm

e

x = 8.2 cm

f

x = 12.3 cm

Answer sheet

Perimeters: code breaker

Find the perimeter of each shape to 1 decimal place.

Find one side with trigonometry, then the third with trigonometry or Pythagoras. Look your answer up in the Code Box.

Code breaker to print

1

Perimeter = 22.8 cm

1. Find the length x to 1 decimal place.

   x = 11.3 cm

2. Find the length x to 1 decimal place.

   x = 7.7 cm

3. Label, pick the ratio, then find x to 1 decimal place.

   x = 9.2 cm

Exit tickets to print