1

Problem

Find the perimeter of the shape.

2

Step

The given shape is an isosceles triangle:

3

Step

The sides of an isosceles triangle are:

a = 10 ft. , b = 5 ft.

4

Formula

The perimeter of an isosceles triangle is P = 2a + b.

5

Clue

Substitute the values by using formula:

P = 2(10) + 5

6

Step

After multiplication we get:

P = 20 + 5

7

Step

After addition we get:

P = 25

8

Solution

Therefore, the perimeter of an isosceles triangle is P = 25 ft.

9

Sumup

Please summarize steps

Choices

10

Choice-A

This is accurate and aligns with the calculated perimeter

Correct 25 ft

11

Choice-B

This is incorrect because it appears to add the sides instead of using the correct formula for the perimeter of an isosceles triangle

Wrong 40 ft

12

Choice-C

This is incorrect as it seems to consider only one side (a) instead of applying the correct formula

Wrong 20 ft

13

Choice-D

This is incorrect because it adds the sides without following the correct formula for the perimeter of an isosceles triangle

Wrong 30 ft

14

Step

Option

A

15

Sumup

Please summarize choices