Name: Construction of Triangle When Base Angles and Perimeter Is Given
Uploaded: 2019-07-19
Duration: 5 min 46 s
Description: A perimeter and the three angles are a must for a triangle to exist. But you don't necessarily need all of these to construct a triangle. Let’s learn how in...

Question

Construct an isosceles triangle one of whose angle is

120 °

and the length of each of equal side is

4 cm

.

Accepted Answer

Since one angle of the isosceles triangle is $4 cm$ , then the equal sides of the isosceles triangle will contain this angle.

Steps of Construction:

(a) Draw a straight line $B C$ of length $4 cm$ . At $B$ draw an arc of any length such that it intersects $B C$ at $X .$

(b) With $X$ as centre and $B X$ as radius, draw an arc such that it intersects the arc drawn in step (a) at $Y$ .

(c) With $Y$ as centre and $B X$ as radius, draw an arc such that it intersects the arc drawn in step (a) at $Z$ .

(d) Join $B Z$ and extend the line up to the point $D$ . Thus, we get, $∠ D B C = 120 °$ .

(e) With $B$ as centre and taking $4 cm$ as radius, draw an arc on $A D$ , such that it intersects $A D$ at $A$ .

(f) Join $A C$ . Hence, we obtain the required isosceles triangle $△ A B C$ with the required circumcircle of $∆ A B C$ , one of whose angle is $120 °$ and the length of each of equal side is $4 cm$ .

Construct an isosceles triangle one of whose angle is $120 °$ and the length of each of equal side is $4 cm$ .

Important Questions on Construction

Learn and Prepare for any exam you want !

Construct an isosceles triangle one of whose angle is 120° and the length of each of equal side is 4 cm.

Important Questions on Construction

Learn and Prepare for any exam you want !

Construct an isosceles triangle one of whose angle is $120 °$ and the length of each of equal side is $4 cm$ .