Equilateral & Isosceles Triangles

When an isosceles triangle has exactly two congruent sides, these two sides are the ___________________

• legs

• vertex angles

• bases

• base angles

• complementary

The angle formed by the legs of an isosceles triangle is the _____________ angle.

• base

• vertex

• acute

• equiangular

• complementary

The third side of the isosceles triangle is the ____________.

• leg

• base

• vertex angle

• base angle

• equilateral

If two angles of a triangle are congruent, then the sides opposite them are ____________________.

• complementary

• adjacent

• supplementary

• congruent

If a triangle is equilateral, then it is _____________________.

• complementary

• supplementary

• vertex

• acute

• equiangular

Find the value of x and choose the theorem you used to find the value.

• x = 50

• x = 25

• x = 30

• by the Base Angles Theorem

• by the Converse to the Base Angles Theorem

Find the value of x and choose the correct theorem used to find the value.

• x = 6

• x = 4

• x = 5

• by the Base Angles Theorem

• by the Converse to the Base Angles Theorem

Find the values of x and y.

• x = 20

• x = 40

• x = 30

• y = 25

• y = 30

Find the values of x and y.

• x = 30

• x = 60

• x = 15

• y = 20

• y = 4

Find the value of x.

• x = 18

• x = 72

• x = 36

• x = 20