Angle Pairs for Kids: Complementary, Supplementary and Vertical Angles (Grade 7 Math)

Hi, I'm Luna from DoodleBeez. Today we are learning about angle pairs. Some pairs of angles have special names and special rules. Knowing them helps you find a missing angle without a protractor.

Complementary angles add up to ninety degrees. Together they make a right angle, like the corner of a page. Here, thirty five degrees and fifty five degrees are complementary, because they add to ninety.

Supplementary angles add up to one hundred eighty degrees. Together they make a straight line. Here, one hundred thirty degrees and fifty degrees sit side by side on a line, so they are supplementary.

When two lines cross, the angles opposite each other are called vertical angles, and they are always equal. Here both seventy degree angles face each other. The angles next to them are each one hundred ten degrees.

Adjacent angles are neighbors. They share a vertex, which is the corner point, and they share one side, but they do not overlap. The seventy degree and one hundred ten degree angles we just saw are adjacent.

We can use equations too. Two supplementary angles measure x and three x. So x plus three x equals one hundred eighty. Four x is one hundred eighty, so x is forty five. The angles are forty five and one hundred thirty five degrees.

Now it's your turn. An angle measures twenty eight degrees. What is its complement, and what is its supplement? Pause and try. The complement is sixty two degrees. The supplement is one hundred fifty two degrees.

Great job! Remember, complementary angles add to ninety, supplementary angles add to one hundred eighty, and vertical angles are equal. Practice angle pairs in Middle School Math at doodlebeez.com. See you next time!