Question

The y axis is a line of symmetry for a triangle. The coordinates of two of its vertices are (-3, 2) and (0,5)

A. What are the coordinates of the third vertex?

B. What is the area of the triangle?

Answer 1

(3,2)

Explanation:

since it symmetrical over the y axis it will be the same as the first point except the x will be the opposite

Answer 2

• See below

Explanation:

A)

One of the points on the y-axis (0, 5).

It means the other vertices are symmetrical:

• (-3, 2) and (3, 2)

B)

The height of the triangle is the difference of the y-coordinates:

• h = 5 - 2 = 3

The base of the triangle is the distance between the symmetric vertices:

• b = 3 - (-3) = 6

The area is:

• A = 1/2bh = 1/2*6*3 = 9 units²