A rectangular piece of card has a perimeter of 40cm and width of 8cm.
1 answer:
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Answer:
40 degrees
Step-by-step explanation:
A triangle solver tool can find the angle easily. It is 39.8°, which rounds to 40°. Apps are available on some calculators, on the Internet, and for iOS and Android phones and tablets.
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You may be expected to solve this using the Law of Cosines. If we name the sides ...
- a = 1.75
- b = 3.00
- c = 2.00
the law of cosines tells us the relationship is ...
c² = a² + b² -2ab·cos(θ)
Then the angle is ...
θ = arccos((a² +b² -c²)/(2ab)) = arccos((3.0625 +9 -4)/(2·1.75·3))
= arccos(8.0625/10.5) ≈ 39.838° ≈ 40°
