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Misc 3 - Practical Geometry
Last updated at August 10, 2026 by Teachoo
Constructing a triangle when 2 angles and side between is known (ASA)
Practical Geometry
Concept wise
- Construction of line parallel to given line, through point not on line
- Constructing a triangle when 3 sides known (SSS)
- Constructing a triangle when 2 sides and angle between is known (SAS)
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Constructing a triangle when 2 angles and side between is known (ASA)
- Constructing a right triangle when hypotenuse and side is given (RHS)
Transcript
Misc 3 Below are given the measures of certain sides and angles of triangles. Identify those which cannot be constructed and, say why you cannot construct them. Construct rest of the triangles. Here, ∠ A + ∠ B = 70° + 50° = 110° < 180° So, Δ ABC is possible But, to construct it, We need to find ∠ Finding ∠ C In Δ ABC, Sum of angles = 180° ∠ A + ∠ B + ∠ C = 180° 70° + 50° + ∠ C = 180° 120° + ∠ C = 180° ∠ C = 180° – 110° ∠ C = 60° Now, let’s construct it Steps of construction 1. Draw a line segment AC of length 3 cm 2. Now, we draw 70° from point A (using protractor) 3. Now, we draw 60° from point C Check Construction 11.3 of Chapter 11 Class 9 NCERT to see how to draw 60° 4. Let point B be the point where the two rays intersect and label the sides Thus, Δ ABC is the required triangle
