A quadrilateral has a perimeter of 42cm. Three sides have equal length and the fourth side is longer by 6cm. What is the length of the fourth side?

We can call the sides of the equal lengths "x".
We can then make an equation to satisfy the relationship between the perimeter and the length of the sides as follows:
x + x + x + (x + 6) = 42
Therefore 4x + 6 = 42
Now subtract 6 from both sides:
4x = 36, so x = 9.
The length of the fourth side is (x + 6) so:
9 + 6 = 15cm

EB

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations: 4x+y=25 and x-3y=16


What is the value of x if x^2 - 3x +2=0?


The distance from the Earth to the Sun is 93 million miles. Assume: it takes 365 days for the Earth to travel once around the Sun and the Earth travels in a circle with the Sun at the centre. Work out the average speed of the Earth in miles per hour.


Sue has a cow farm. Her cows produced on average 25 litres of milk every day for 55 days. Sue bottles the milk in 1/2 litre bottles. How many bottles will Sue need to bottle all the milk.