Chapter 6.5, Problem 9CE

a)

To determine

To draw: an isosceles triangle with legs 7 cm long and vertex angle of 3

  $120°$ . To measure the length of the base of the triangle.

Answer to Problem 9CE

The above figure the third side is length of 12cm.

Explanation of Solution

Calculation:

To draw an isosceles triangle with legs 7 cm long and a vertex angle of 120 degrees and to find length of its base.

Consider the following figure:

  

Therefore, from the above figure the third side is length of 12cm.

b)

To determine

To explain: the length of the base. The new triangle and the length of third side.

Answer to Problem 9CE

The new triangle is an equilateral triangle.

The third side becomes 7cm.

And, the base is also 7 cm.

Explanation of Solution

Given information:

The legs at 7cm in length and the measure of the vertex angle to $60°$ .

Calculation:

To draw an isosceles triangle with legs 7 cm long and a vertex angle of 60 degrees and to find length of its base.

Consider the following figure:

  

Therefore, the new triangle is an equilateral triangle.

So, in equilateral triangle base are same.

Therefore, the third side becomes 7cm.

And, the base is also 7 cm.