Question

across
1 a triangle in which one of the interior angles measures more than 90° is called ______
5 the side opposite the right angle of a right triangle is called the ______
7 a triangle whose all three sides are of equal length is called a(n) ______ triangle
9 if two sides and the included angle in one triangle are congruent to two sides and the included angle in another triangle, then the two triangles are congruent by side ______ side.
11 a triangle in which one of the interior angles is 90° is called a(n) ______ triangle
13 a triangle that has two equal sides is called a(n) ______ triangle
down
2 a triangle whose all three sides have different lengths, and all three angles are of different measures is called a(n) ______ triangle
3 the side of an isosceles triangle that is not one of the legs is called a ______
4 a pair of sides or angles that have the same relative position in two congruent figures are called ______ parts.
6 a triangle in which angles are congruent and all sides are of equal length is called a(n) ______ triangle
8 a triangle with three angles, all less than 90° is called a(n) ______ triangle.
10 when an isosceles triangle has exactly two congruent sides, these congruent sides are called the ______
12 angles that lie inside polygon are called ______ angles
14 if three sides of a triangle is equal to the corresponding sides of the other triangle, the two triangles are said to be congruent side ______ side.
15 angles that form linear pairs with the interior angles of a polygon are called ______ angles.
congruent triangles (with a crossword puzzle grid)

Explanation:

Across:

1. A triangle with one angle > 90° is obtuse.
2. The side opposite the right angle in a right triangle is the hypotenuse.
3. A triangle with all three sides equal is an equilateral triangle.
4. The congruence criterion for two sides and the included angle is side - angle - side (SAS) (so the missing word is "angle").
5. A triangle with one 90° angle is a right triangle.
6. A triangle with two equal sides is an isosceles triangle.

Down:

1. A triangle with all sides and angles different is a scalene triangle.
2. The non - leg side of an isosceles triangle is the base.
3. Corresponding parts of congruent figures are called corresponding parts.
4. A triangle with congruent angles and equal sides (same as equilateral) is equilateral (or "regular", but equilateral is more precise here).
5. A triangle with all angles < 90° is an acute triangle.
6. The congruent sides of an isosceles triangle are the legs.
7. Angles inside a polygon are interior angles.
8. The congruence criterion for three equal sides is side - side - side (SSS) (missing word is "side").
9. Angles forming linear pairs with interior angles are exterior angles.

Answer:

(Filling the Crossword):

• Across 1: OBTUSE
• Across 5: HYPOTENUSE
• Across 7: EQUILATERAL
• Across 9: ANGLE
• Across 11: RIGHT
• Across 13: ISOSCELES
• Down 2: SCALENE
• Down 3: BASE
• Down 4: CORRESPONDING
• Down 6: EQUILATERAL
• Down 8: ACUTE
• Down 10: LEGS
• Down 12: INTERIOR
• Down 14: SIDE
• Down 15: EXTERIOR