Find the area of a triangle whose vertices have coordinates (3, 17) (16, 19) (16, 25)

Let the vertex be A (3; 17), B (16; 19), C (16; 25).

Finding the lengths of segments by coordinates and applying Heron’s formula is not advisable, since the lengths of the segments are obtained under the root sign.

Then we apply the following formula:

Savs = | (X2 – X1) * (Y3 – Y1) – (X3 – X1) * (Y2 – Y1) | / 2 =

| (16 – 3) * (25 – 17) – (16 – 3) * (19 – 17) | / 2 = | 13 * 8 – 13 * 2 | / 2 = 78/2 = 39 cm2.

Answer: The area of the triangle is 39 cm2.