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**Calculating the Lengths of Corresponding Sides**

- Step 1: Find the ratio. We know all the sides in
**Triangle**R, and. We know the side 6.4 in**Triangle**S. - Step 2: Use the ratio. a faces the angle with one arc as does the side of length 7 in
**triangle**R. a = (6.4/8) × 7 = 5.6.

Herein, what is the formula for similar triangles?

Ratios and Proportions - **Similar figures** - In Depth. If two objects have the same shape, they are called "**similar**." When two **figures** are **similar**, the ratios of the lengths of their corresponding sides are equal. To determine if the **triangles** shown are **similar**, compare their corresponding sides.

**similar triangles**, corresponding sides are always in the same ratio. For

**example**:

**Triangles**R and S are

**similar**. The equal angles are marked with the same numbers of arcs.

Then, how fo you find the area of a triangle?

To **find** the **area** of a **triangle**, multiply the base by the height, and then divide by 2. The division by 2 comes from the fact that a parallelogram can be divided into 2 **triangles**. For example, in the diagram to the left, the **area** of each **triangle** is equal to one-half the **area** of the parallelogram.

Two lines that intersect and form right angles are called **perpendicular** lines. The **symbol** ⊥ is used to denote **perpendicular** lines. In Figure , line l ⊥ line m.