This post is about finding ratio of areas for 2 figures. These types of questions often comes out in Emaths Vectors, Similar figures questions like this question shown.
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Follow these 3 rules to solve these types of questions.
- Check if the 2 figures shares a common height. Then proceed to write out the formulae of their area leaving the common height unknown in the fraction. The unknown height will be cancelled out in the fraction.
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2. Check if the figures are similar. For similar figures, apply this formulae. A1/A2 = (l1/l2)square
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3. Check if the 2 figures shares a common area. Then proceed to form fraction expressions of the 3 different areas. Lastly, form an equation to get the ratio of the 2 areas asked in the question.
This last type of question needs some practice and students will get the concept to solve them in no time. 🙂