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.

 $Are{a}_{triangle}= \frac{1}{2}\times b\times h$, 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: $A_{triangle}=\frac{1}{2}\times b\times h$ $=\frac{1}{2}\times 6\times 5$ $=15 c{m}^2$

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

Solution: $A_{triangle}=\frac{1}{2}\times b\times h$ $=\frac{1}{2}\times 4\times 5.5$ $=11 c{m}^2$

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

Solution: $A_{triangle}=\frac{1}{2}\times b\times h$ $=\frac{1}{2}\times 4\times 5.5$ $=6.3 i{n}^2$

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

Solution: $A_{triangle}=\frac{1}{2}\times b\times h$ $=\frac{1}{2}\times 2\times 7$ $=7 i{n}^2$

Cheat Sheet

• $Are{a}_{triangle}=\frac{1}{2}\times b\times h$, where $b=$length of the base, and $h=$height of the triangle

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Blunder Areas

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