Question

the sides of a triangle, in centimetres,are x,2x-3 and 2x+5. The perimeter of the triangle is 57 cm.a)write down an equation for x. b)work out the lengths of three sides of the triangle

Answer 1

11 cm, 19 cm, 27 cm

Explanation:

Triangles have 3 sides and perimeter is the sum of all side lengths. So the equation is x + (2x-3) + (2x+5) = 57.

x + (2x-3) + (2x+5) = 57

x + 2x - 3 + 2x + 5 = 57

x + 2x + 2x - 3 + 5 = 57

5x + 2 = 57

5x = 57 -2

5x = 55

x = 11

Now that we know the value of x, we can figure out the side lengths. The first side (x) is 11 cm long, the second side (2x - 3) is 19 cm, and the third side (2x + 5) is 27 cm long.

Answer 2

Answer with step by step explanation

The perimeter of a triangle is the sum of the sides.

There fore,

a) x + 2x - 3 + 2x + 5 = 57

Now, let us solve the above equation and find the value of x.

Let us solve.

x + 2x - 3 + 2x + 5 = 57

Combine like terms.

5x -3 + 5 = 57

5x + 2 = 57

5x = 57 - 2

5x = 55

Divide both sides by 5.

x = 11

And now they've asked us to write the lengths of three sides.

Let us write now.

b) x = 11 cm

( 2x - 3 ) ⇒ ( 2 × 11 - 3 ) ⇒ ( 22 - 3 ) ⇒ 19 cm

( 2x + 5 ) ⇒ ( 2 × 11 + 5 ) ⇒ ( 22 + 5 ) ⇒ 27 cm

Let me know if you have any other questions. :)