Key Points
Key Points: Construction of Similar Triangle
Case (i): When vertices are distinct
- Calculate sides using ratio → construct new triangle
Case (ii): When one vertex is common
- Divide side → draw a parallel line → similar triangle
Key Points: Construction of Tangent to a Circle at a Point
Using Centre:
-
Radius ⟂ tangent at the point of contact
Without Using Centre:
- Angle between tangent and chord = angle in the opposite arc
(Converse of tangent–secant angle theorem)
Key Points: Construction of Tangent from a Point Outside Circle
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Angle in a semicircle is 90°
-
Tangents from an external point are equal
Important Questions [4]
- Draw an Equilateral ΔABC with Side 6.2 cm and Construct Its Circumcircle
- Find the Length of the Altitude of an Equilateral Triangle with Side 6 Cm
- ∆ABC ~ ∆LMN. In ∆ABC, AB = 5.5 cm, BC = 6 cm, CA = 4.5 cm. Construct ∆ABC and ∆LMN such that BCMNBCMN=54.
- Draw a Triangle Abc with Side Bc = 6cm, ∠B = 45° And ∠A = 100°, Then Construct a Triangle Pbq Whose Sides
Concepts [4]
- Construction of Similar Triangle
- Construction of a Tangent to a Circle at a Point on the Circle
- Construction of a Tangent to a Circle from a Point Outside the Circle
- Overview of Geometric Constructions
