Question

$△$ABC is drawn with the length of side AB being 6 cm. If $\angle$A is 65${}^{\circ }$ and $\angle$B is 65${}^{\circ }$, then $△$ABC is

• A. a scalene triangle
• B. an isosceles triangle
• C. an obtuse angled triangle
• D. an equilateral triangle

Answer 1

The correct option is B

an isosceles triangle

Steps of construction of $△$ABC:

Step 1:
Draw the base line AB of the length 6 cm.

Step 2:
Measure the angle A with your protractor. Make a mark at 65 degrees and draw a line from A passing through the mark.

Step 3:
Measure the angle B with your protractor. Make a mark at 65 degrees and draw a line from B passing through the mark.

Step 4:
Name the point of intersection of these two lines as C and the $△$ABC is complete, as shown below.

Now, from the above construction we see that the length of side AC is equal to the length of side BC, which is 7.1 cm

Hence, the constructed triangle is an isosceles triangle.