Right Trapezoid Calculator

Calculate area, perimeter, sides, angles, and median of a right trapezoid

Enter Trapezoid Dimensions

Enter any three dimensions to calculate all trapezoid properties

The longer parallel side

The shorter parallel side

The perpendicular side (height)

The diagonal side

Calculated Dimensions

0.000
Longer Base (a)
0.000
Shorter Base (b)
0.000
Height (c)
0.000
Slant Side (d)

Properties

0.00
Area
Square units
0.00
Perimeter
Linear units
0.00
Median
Midsegment length
90°
Right Angles
Two right angles
90.0°
Acute Angle
At slant side
90.0°
Obtuse Angle
Supplementary angle

Example Calculation

Right Trapezoid with a = 10, b = 6, c = 5

Given: Longer base (a) = 10 units, Shorter base (b) = 6 units, Height (c) = 5 units

Step 1: Calculate slant side: d = √[(a - b)² + c²] = √[(10 - 6)² + 5²] = √[16 + 25] = √41 ≈ 6.40 units

Step 2: Calculate area: A = (a + b) × h / 2 = (10 + 6) × 5 / 2 = 40 sq units

Step 3: Calculate perimeter: P = a + b + c + d = 10 + 6 + 5 + 6.40 = 27.40 units

Step 4: Calculate median: m = (a + b) / 2 = (10 + 6) / 2 = 8 units

Step 5: Calculate acute angle: α = arctan(c / (a - b)) = arctan(5 / 4) = 51.34°

Right Trapezoid Properties

Has exactly two parallel sides (bases)

Contains exactly two right angles (90°)

One side is perpendicular to both bases

Height equals the perpendicular side length

Easier to calculate than general trapezoids

Key Formulas

Area

A = (a + b) × h / 2

Perimeter

P = a + b + c + d

Slant Side

d = √[(a - b)² + c²]

Median

m = (a + b) / 2

Quick Facts

A rectangle is also a right trapezoid

Cannot have just one right angle

Height = perpendicular side length

Sum of all angles = 360°

Understanding Right Trapezoids

What is a Right Trapezoid?

A right trapezoid is a special type of trapezoid that has exactly one leg perpendicular to both of its parallel bases. This means it contains exactly two right angles (90°). The perpendicular leg serves as the height of the trapezoid, making calculations much simpler than for general trapezoids.

Key Components

  • Longer Base (a): The longer of the two parallel sides
  • Shorter Base (b): The shorter of the two parallel sides
  • Height (c): The perpendicular side (also the trapezoid's height)
  • Slant Side (d): The non-perpendicular leg connecting the bases

Calculation Methods

Area Formula

A = (a + b) × h / 2

Average of parallel sides times height

Pythagorean Relationships

d = √[(a - b)² + c²]

Used to find missing side lengths

Angle Calculations

α = arctan(c / (a - b))

Find acute angle at slant side

Median (Midsegment)

m = (a + b) / 2

Line parallel to bases through midpoint