Haruto says the area of the triangle can be calculated using the following formula: A= 1/2·circumference·radius

Use this fact to convince a friend that the area of a circle is A=π·r2.

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since the cosine is the ratio of the adjacent side to the hypotenuse, you can see that cos 60° = ½. answer. according to the property of cofunctions (topic 3), sin 30° is equal to cos 60°. sin 30° = ½.

Number 40 is a rational number glad i could