Question

100 POINTS FOR 2 QUESTIONS!!

Answer 1

11.a

=solution

Perimeter of triangle =A+B+C

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

=4x+4

4(x+1)cm

Therefore, 4(x+1) cm is the perimeter of the given triangle.

b.

=solution

given,

length(l)=3y+1

breadth(b)=y-2

Now,

perimeter of rectangle=2*(l+b)

=2*(3y+1+y-2)

=2*(4y-1)

=8y-2 cm

Therefore, 8y-2 cm is the perimeter of the given rectangle.

Answer 2

`\textsf{(a)} \quad 4x+4`

`\textsf{(b)} \quad 8y-2`

Explanation:

The perimeter of a two-dimensional shape is the distance all the way around the outside.

Part (a)

The perimeter of the given triangle is the sum of the lengths of its sides:

`\begin{aligned}\sf Perimeter & = (2x-3)+(x+2)+(x+5)\\& = 2x-3+x+2+x+5\\& = 2x+x+x+5+2-3\\& = 4x+4\end{aligned}`

Part (b)

A rectangle has two pairs of parallel, congruent sides.

Therefore, the perimeter of the given rectangle is twice the sum of its two different sides:

`\begin{aligned}\sf Perimeter & = 2(3y+1+y-2)\\& = 2(3y+y+1-2)\\& = 2(4y-1)\\&=8y-2\end{aligned}`