Download MA.8.G.2.3 Demonstrate that the sum of the angles in a triangle is

MA.8.G.2.3 Demonstrate that the sum of the angles in a triangle is 180-degrees and apply this fact to find unknown
measure of angles, and the sum of angles in polygons.
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In a regular polygon
all sides are
congruent and all
angles are congruent.
How do you find the measure of a single interior angle of a regular polygon?
What if we have a problem like this:
What is the measure of angle T?
You know that the 4 angles of a quadrilateral add up to 360o
You know that angle R = 90 o
You know that angle Q and angle T are congruent based on the curve and tick
mark. Let’s call them x.
So, set up an equation:
**NO NEED TO MEMORIZE THESE FORMULAS…THEY WILL BE ON THE REFERENCE SHEET:
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MA.8.G.2.3 Practice Problems
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An irregular heptagon has angles that measure x°, x°, 2x°, 2x°,
3x°, 3x°, and 4x°. What is the measure of x?
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What is the measure of x?
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A trapezoid has angles that measure 3x°, 3x°, x°, and x°. What
is the measure of x?
10.
How many sides does a regular polygon have if the
measure of an interior angle is 171°?
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11. What is the measure of
Angle A? Angle B? Angle C?
12. A bathroom tile consists of regular hexagons
surrounded by regular triangles as shown below. Find
the measure of one interior angle in both the hexagon
and the triangle tiles.
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Vertices Q and T of ΔQTU are located on opposite sides of
rectangle PRSU, as shown in the diagram below. What is the
measure of x?
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