Royal College, Colombo 07 11 ශ්‍රේණිය ගණිතය 1 වාර පරීක්ෂණය 2021

Price of one item from the price of three

පිළිතුර: Rs. 24

💡 ප්‍රශ්නයේ අදහස: දොඩම් 3 ක මිල දන්නා විට එකක මිල යනු මුළු මිල 3 න් සමව බෙදීමයි.

1. 1දොඩම් 3 ක මිල රු. 72.
2. 23 න් බෙදන්න: 72 ÷ 3 = 24.
3. 3එක් දොඩමක මිල රු. 24.

✅ පරීක්ෂාව: 3 × 24 = 72. ✓

Angle in a triangle using parallel lines

පිළිතුර: x = 40

💡 ප්‍රශ්නයේ අදහස: සරල රේඛාවක කෝණ, ඉන්පසු සමාන්තර රේඛා (ඒකාන්තර කෝණ), ඉන්පසු ABC ත්‍රිකෝණයේ කෝණ එකතුව යොදන්න.

1. 1AD සරල රේඛාව මත: EBA = 180 − 120 = 60°.
2. 2AC ∥ EB සහ AB ඒවා කපයි; CAB = ABE = 60° (ඒකාන්තර කෝණ, 'Z' හැඩය).
3. 3ABC ත්‍රිකෝණයේ: x = 180 − 60 − 80 = 40°.

✅ පරීක්ෂාව: 60 + 80 + 40 = 180. ✓

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