Using ruler and compass, construct a triangle ABC, where AB = 3 cm, BC = 4 cm and ∠ABC = 90°. Hence, construct a circle circumscribing the triangle ABC. Measure and write down the radius of the circle.

Steps of construction :

1. Draw a line segment AB = 3 cm.

2. From B, draw a ray BX such that ∠XBA = 90°.

3. From B draw an arc of 4 cm cutting XB at C.

4. Join AC. ABC is the required triangle.

5. Construct perpendicular bisectors of AB and AC, such that they intersect at O.

6. With O as center and OA as radius draw a circle passing through A, B and C.

7. Measure OA.

Hence, above is the required circumcircle of triangle ABC.

On measuring we get OA = 2.5 cm.

Hence,the length of the radius of the circle = 2.5 cm.