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Please help me, the image is attached below. It's a geometry question.

Please help me, the image is attached below. It's a geometry question.-example-1
User Ilkka
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2 Answers

6 votes
why did you delete my answer

just do 30 = 1/2xy sin 70 and then 60 = xy sin 70 and then 60/sin70 = xy

and then do area = 1/2 xy sin110 and then do area = 1/2 (60 / sin70) sin110 and then do area = 30
User Rosencreuz
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5.8k points
2 votes
Hey there!

To start, none of these triangles appear to have a given height, only a given angle. Another thing to notice is that neither of these triangles are right. This means that you would need to use the function of sine to calculate the area of the triangle.

First, you know that the sine triangle area formula is:
A= 1/2*side*side*sin(given angle)

Knowing that the area of ΔABC is 30, the sides given are x and y, and the angle is 70, you can set up this equation:
1/2*xy*sin(70)=30

Now, solve for xy:
2(1/2*xy*sin(70)=30)
=xy*sin(70)=60
=xy=60/(sin(70))

Now, use the same formula to solve for the area of ΔPQR knowing that xy=60/(sin(70)).

1/2*60/(sin(70))*sin(110)
=30 cm squared

Therefore, the correct answer would be 30.

Hope this helps!
User KillianGDK
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