Calculate Triangle Area: Finding Area with Sides 13cm, 15cm, and Height from Point D

Question

The triangle ABC has a perimeter measuring 42 cm.

AD = 12

AC = 15

AB = 13

Calculate the area of the triangle.

131313151515121212AAABBBCCCDDD

Video Solution

Solution Steps

00:00 Calculate the area of triangle ABC
00:04 Substitute appropriate values according to the data
00:13 The perimeter of the triangle equals the sum of the sides
00:23 Substitute appropriate values according to the data
00:34 Calculate and solve to find BC
00:47 Isolate BC
00:58 This is the base length BC
01:02 Calculate the area of triangle ABC
01:05 Use the formula for calculating triangle area
01:08 (height(AD) multiplied by base(BC)) divided by 2
01:12 Substitute appropriate values
01:16 Calculate and solve
01:25 And this is the solution to the problem

Step-by-Step Solution

Given that the perimeter of triangle ABC is 42.

We will use this data to find side CB:

13+15+CB=42 13+15+CB=42

CB+28=42 CB+28=42

CB=4228=14 CB=42-28=14

Now we can calculate the area of triangle ABC:

AD×BC2=12×142=1682=84 \frac{AD\times BC}{2}=\frac{12\times14}{2}=\frac{168}{2}=84

Answer

84 cm²