Download NAME Period: ______ Date : ______ Isosceles Triangles

NAME _______________________ Period: ____________ Date : ____________
Isosceles Triangles
An Isosceles Triangle has 2 _________ _________ and 2
_________ _________.
The base angles of an isosceles triangle are _________.
Find the measures of the missing angles and/or the lengths of the sides.
Isosceles Triangles Worksheet #1
Name _________________
October 13, 2011 Thursday
Draw a picture to help find the missing sides or angles!!
1. The vertex angle of an isosceles triangle is 40 . What is the measure of one base angle?
2. One base angle of an isosceles triangle is 73 . What is the measure of the vertex angle?
3. The degree measure of the vertex angle is (7x - 27) . The degree measure for each base
angle is (9x - 34) . What is the value of one base angle?
4. The ratio of the measure of a base angle in an isosceles triangle to the measure of the
vertex angle is 2:16. Find the measure of each angle.
5. The degree measure of the vertex angle is (3x - 8) . The degree measure for each base
angle is (6x - 41) . What is the value of vertex angle?
6. The degree measure of the vertex angle is (x + 21) . The degree measure for each base
angle is (2x + 17) . What is the value of x?
7. The vertex angle of an isosceles triangle is 76 . What is the measure of one base angle?
8. The ratio of the measure of a base angle in an isosceles triangle to the measure of the
vertex angle is 1:7. Find the measure of each angle.
Isosceles Triangle picture problems ANSWERS
1. 70 degrees
2. x = 112 degrees, y = 34 degrees, z = 14
3. a=b=11; x = 8, base angles are 71 degrees
4. x=3, the lengths of the sides are 25
5. a=90 degrees k = 16 and s = 68 degrees
6. 144 degrees
Isosceles Triangles Worksheet #1 - ANSWERS
1. 70
2. 34
3. 65
4. each base is 18 and the vertex is 144
5. 46
6. 25
7. 52
8. each base is 20 and the vertex is 140