1. Constructing a triangle
Sunday, 21 April 2019
Constructing a triangle
given one side and two angles

2. Construct triangle ABC when 𝐴𝐵 =9cm, 𝐴 𝐵 𝐶=60° and 𝐵 𝐴 𝐶=35°
Example
Construct triangle ABC when 𝐴𝐵 =9cm, 𝐴 𝐵 𝐶=60° and 𝐵 𝐴 𝐶=35°
Measure and write down the length of AC C
Step 1 draw the line AB = 9cm
Step 2 place the protractor onto B and measure 60 degrees and draw a line
Step 3 place the protractor onto A and measure 35 degrees draw a line which intersects the line drawn
The point of intersection is point C
The triangle is completed by drawing lines from C to A and C to B A B

3. Construct triangle DEF when DE =5.7cm, 𝐷 𝐸 𝐹=74° and 𝐸 𝐷 𝐹=74°
Example
Construct triangle DEF when DE =5.7cm, 𝐷 𝐸 𝐹=74° and 𝐸 𝐷 𝐹=74°
Measure and write down the length of EF F D E

4. Construct triangle PQR when PQ =4.7cm, 𝑃 𝑄 𝑅=128° and Q 𝑃 𝑅=25°
Example
Construct triangle PQR when PQ =4.7cm, 𝑃 𝑄 𝑅=128° and Q 𝑃 𝑅=25°
Measure and write down the length of QR R P Q

5. Constructing a rectangle
Example
Construct a rectangle with dimensions 8cm by 6cm
Step 1 draw a line 8cm long
Step 2 using the protractor measure an angle of 90 degrees and draw a line 6cm long
Step 3 using the compasses set to 8cm place the point at the top of the 6cm line and draw an arc.
Step 4 compasses now set to 6cm place the point on the other end of the 8cm line and draw an arc
Step 5 finally draw two lines to the point of intersection of the arcs completing the rectangle