Question

The length of a straight line ABC is 5m. If AB:BC= 2:5, find the length of AB

Answer 1

To find the length of AB, set up a proportion using the ratio AB:BC = 2:5 and solve for AB. The length of AB is 2 meters.

Step-by-step explanation:

To find the length of AB, we can set up a proportion based on the ratio between AB and BC. The ratio AB:BC is 2:5, so we can set up the equation AB/BC = 2/5. Since the length of BC is 5m, we can substitute this value into the equation to get AB/5 = 2/5. Cross-multiplying, we find that AB = (2/5) * 5 = 2m. Therefore, the length of AB is 2 meters.

Answer 2

`(10)/(7)\approx 1.43\text{ m}`.

Step-by-step explanation:

We have been given the length of a straight line ABC is 5 m. We are asked to find the length of AB, when
`AB:BC=2:5`.

We can represent our given ration as:

`(AB)/(BC)=(2)/(5)`

We can write above ratio in terms of AC as:

`(AB)/(AB+BC)=(2)/(2+5)`

`(AB)/(AC)=(2)/(2+5)`

Upon substituting
`AC=5`, we will get:

`(AB)/(5)=(2)/(7)`

`(AB)/(5)*5=(2)/(7)*5`

`AB=(2*5)/(7)`

`AB=(10)/(7)=1.42857`

Therefore, the length of AB is
`(10)/(7)\approx 1.43\text{ m}`.