#### Transcript of Writing Algebraic Equations

2nd step

**5th Step**

3rd step

Reread

**4th step**

1st Step

**Writing Algebraic Equations**

Read the word problem

Don't just read it once. Reread the problem as you solve it to make sure you don't miss anything.

Define the variable

The perimeter of an isosceles triangle is 20 cm. What is the length of its base if the sides are 8.5 cm?

Ask yourself:

"What am I being asked to find?"

b = base of triangle

The perimeter of an isosceles triangle is 20 cm. What is the length of its base if the sides are 8.5 cm?

Restate the problem.

Ask yourself:

"What information am I being given?"

Ask yourself:

"What do I already know about this situation?"

The perimeter of an isosceles triangle is 20 cm. What is the length of its base if the sides are 8.5 cm?

The perimeter of an isosceles triangle is 20 cm. What is the length of its base if the sides are 8.5 cm?

perimeter means the sum of all sides

isosceles triangles have 2 congruent (equal) sides

The first side plus the second side plus the base equals the perimeter.

Translate the problem from words to symbols.

The first side plus the second side plus the base equals the perimeter.

The perimeter of an isosceles triangle is 20 cm. What is the length of its base if the sides are 8.5 cm?

Ask yourself:

"What operations are being desribed in the problem?"

Ask yourself:

"What do these words mean?"

8.5 + 8.5 + b = 20

**Last Step**

Solve the problem.

Ask yourself:

"What steps can I take to determine the value of the variable?"

8.5 + 8.5 + b = 20

17 + b = 20

17 + 3 = 20

b = 3

Answer the question.

The perimeter of an isosceles triangle is 20 cm. What is the length of its base if the sides are 8.5 cm?

The base is 3 cm.

Ask yourself:

"Am I done?"

Ask yourself:

"Have I answered the question that was asked?"

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