Solving a right triangle (round to the nearest tenth)

see explanation

Step-by-step explanation:

The sum of the 3 angles in a triangle = 180°

Subtract the sum of the given angles from 180 for B

B = 180° - (90 + 40)° = 180° - 130° = 150°

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sin40° = =

Multiply both sides by 21

21 × sin40° = a, thus

a ≈ 13.5 ( to the nearest tenth )

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cos40° = =

Multiply both sides by 21

21 × cos40° = b, thus

b ≈ 16.1 ( to the nearest tenth )

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5