7th Grade - Area of Triangles

Introduction

  • A triangle is a closed polygon formed by three line segments (sides).
  • It has three sides, three angles, and three vertices.

 

Area of Triangles

  • The area of a triangle is the region enclosed by its three sides.
  • The area of different triangles differs based on their size.
  • If we know the base’s length and the triangle’s height, we can determine its area using the formula mentioned below.

 Areatriangle= 12×b×h, where b=length of the base, and h=height of the triangle

Solved Examples

Example 1: Find the area of the triangle shown below.

Solution: Atriangle=12×b×h =12×6×5 =15 cm2

Example 2: Find the area of the triangle shown below.

Solution: Atriangle=12×b×h =12×4×5.5 =11 cm2

Example 3: Find the area of the triangle shown below.

Solution: Atriangle=12×b×h =12×4×5.5 =6.3 in2

Example 4: Find the area of the triangle shown below.

Solution: Atriangle=12×b×h =12×2×7 =7 in2

Cheat Sheet

  • Areatriangle=12×b×h, where b=length of the base, and h=height of the triangle

Blunder Areas

  • It is vital to identify a triangle’s base and perpendicular height.