Show model answer and explanation
17
√(64+225)=17.
Class 8 · Bangla Version · Mathematics
Geometry, measurement and trigonometry readiness
Apply Pythagoras and similarity only when their conditions hold.
About this lesson and its coverage
Original Kidemy Class 8 progression. This level has its own text, examples and questions. Curriculum versions share the progression; complete board-specific coverage still needs specification matching and additional material.
Learn the idea
Pythagoras needs a right triangle. Similar shapes have equal corresponding angles and proportional corresponding lengths. A length scale factor k gives area scale factor k² and volume factor k³.
Worked example
A right triangle with legs9 and 12 has hypotenuse 15. A similar shape enlarged by 2 has4 times the area.
- Identify the quantities and restrictions.
- Show a method with units or symbols.
- Check and explain the result.
Your written practice
Show your working on paper. Check your answer, then choose Next.
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9
3²=9.
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10
Pythagoras gives √100.
Write in your own words. A guardian or teacher should review this response.
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Appearance does not prove equal corresponding angles or proportional sides.
State evidence needed.
Write in your own words. A guardian or teacher should review this response.
Show model answer and explanation
h/12=1.5/2, so h=9m.
State the equal-light-angle and level-ground assumptions.
Progress and browser storage
Notebook challenge, sources and further study
Apply the idea
Draw and solve a scale or shadow problem with its assumptions labelled.
Review with a guardian or teacher
- Use the stated evidence or givens.
- Show reasoning rather than only a result.
- Review and explain one correction.
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