Question

A triangle has perimeter 38 cm.

Two sides of the shapes are put
together to make a pentagon
A square has perimeter 48 cm.
What is the perimeter
of the pentagon?
cm

Answer 1

62cm

Explanation:

You were told the perimeter of the triangle is 38

but two sides are added to make a Pentagon. and that Pentagon is made up of a triangle and a square.

so if we find the side of the square, we can equally get the other two sides of the triangle.

hint: (because it's a square, we would be getting an isosceles triangle, meaning two sides are equal)

because one side of the pentagon added to the other two sides of the triangles gives us the perimeter of the triangle.

we first find the sides of the square with all sides equal by diving by 2

`(48)/(2) = 12`

the sides of the square making the perimeter of the square 12cm.

now we subtract 12 from the perimeter of the triangle 38

`38 - 12 = 26`

now that we have gotten one side we can get the other two by dividing the result by 2

`(26)/(2) = 13`

so the other two sides of the triangle are 13cm.

now since we have the sides of the square and the triangle, we can find the perimeter of the pentagon by adding.

all the sides of the triangle without the base which is also the top of the square.

so instead of adding 4 times of 12, we add 3 times of 12 and 2 times of 13.

3(12)+2(13) = 62

or

12 + 12 + 12 + 13 + 13 = 62cm