What is the sum to this question

(4 + 5) ÷ 3 x 4.

We will use the operation PEMDAS.

So we solve for the parentheses first which is 4 + 5.

That equals 9.

Then we divide 9 by 3 and that equals 3.

Lastly, multiply 3 by 4 and gets you the answer of 12.

x=20°

Step-by-step explanation:

Given that , an isosceles triangle, has the ratio of the measure of the vertex to the measure of a base angle is 1:4, we want to find the measure of the vertex angle.

Note that the base angles of an isosceles triangle are equal.

Therefore if the vertex angle is x, then the base angles are:

4x each

The sum of angles in a triangle is 180°

The vertex angle is 20°