Math 7 - Ch. 7 Review
If a quadrilateral has a 100 degree angle, a 85 degree angle and a 95 degree angles, what is the measure of the 4th angle?
100 + 85 + 95 + d = 360 280 + d = 360 Subtract 280 from both sides d = 80 degrees
If two angles are supplementary and one of them has a measure of 119 degrees, what is the measure of the other angle?
180 - 119 = 61 degrees
If two angles are complementary and one of them has a measure of 52 degrees, what is the measure of the other angle?
90 - 52 = 38 degrees
Vertical Angles
A pair of opposite congruent angles formed by intersecting lines.
Right Triangle
A triangle that has a 90 degree angle.
Acute Triangle
A triangle with 3 acute angles
Equiangular Triangle
A triangle with 3 congruent angles
Obtuse Triangle
A triangle with one angle that is greater than 90 degrees.
Equilateral Triangle
A triangle with three congruent sides
Tell whether these angles are adjacent or vertical.
Adjacent
Straight Angle
An angle that measures 180 degrees
Right Angle
An angle that measures exactly 90 degrees
Acute Angle
An angle that measures less than 90 degrees
Obtuse Angle
An angle that measures more than 90 degrees but less than 180 degrees
If two angles are complementary and one angle is x degrees and the other angle is 2x + 15, then what is the value of x?
x + 2x + 15 = 90 3x + 15 = 90 3x = 75 x = 25 degrees
Solve for x. A triangle has one angle that is x degrees, another angle that is 4x degrees and one more that is 3x degrees. What is the value of x?
x + 4x + 3x = 180 Combine like terms 8x = 180 Divide both sides by 8 x = 22.5
Solve for x. A quadrilateral has two angles that are x degrees and two angles that are 5x degrees. What is the value of x?
x + x + 5x + 5x = 360 Combine like terms 12x = 360 divide both sides by 12 x = 30
If two angles are supplementary and one angle is x - 5 degrees and the other angle is 3x + 10, what is the value of x?
x - 5 + 3x + 10 = 180 4x + 5 = 180 4x = 175 x = 43.75 degrees
Adjacent Angles
Two angles that share a common side and have the same vertex.
Supplementary Angles
Two angles whose measures have a sum of 180 degrees
Complementary Angles
Two angles whose measures have a sum of 90 degrees
Tell whether these angles are adjacent or vertical.
Vertical
If two angles are vertical and one measures 26 degrees, what is the measure of the other vertical angle?
Vertical angles are congruent so the other angle measures 26 degrees. They are the same.
If a triangle has one angle that is 34 degrees and another that is 88 degrees, then what is the measure of the third angle?
a + b + c = 180 34 +88 +c = 180 122 + c = 180 c = 58 degrees
Isosceles Triangle
a triangle with at least two congruent sides
Scalene Triangle
a triangle with no congruent sides
Sum of the Angle measures of a Quadrilateral
The sum of the angle measures of a quadrilateral is 360 degrees. a + b +c + d = 360 degrees
Sum of the Angle Measures of a Triangle
The sum of the angle measures of a triangle is 180 degrees. a + b +c = 180 degrees
