Geometry of Circle

Inscribed Triangle on Diameter - Missing Angle (Level 1)

This math topic focuses on the geometry of circles, specifically working with inscribed triangles where one side is the diameter. The main skill practiced is solving for missing angles within these triangles. Each problem presents a different triangle inscribed in a circle, with one angle given and the student required to find another. The problems invite the student to apply the theorem that a triangle inscribed in a circle and subtended by the diameter is a right triangle. Various angle values are presented in a multiple-choice format for students to select the correct answer.

Work on practice problems directly here, or download the printable pdf worksheet to practice offline.

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Inscribed Triangle on Diameter - Missing Angle

Complete these online problems with 80% or 4 correct answers in a row. Results are immediate.

10

Find angle BNM in degrees given that BMN is 20º and NM forms a diameter

NMB

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Geometry of Circles - Inscribed Triangle on Diameter - Missing Angle Worksheet

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Math worksheet on 'Geometry of Circles - Inscribed Triangle on Diameter - Missing Angle (Level 1)'. Part of a broader unit on 'Geometry - Intermediate - Intro' Learn online: app.mobius.academy/math/units/geometry_intermediate_intro/
1
An svg image showing a math problem
Find angle CZM in degrees given that CMZ is 70º and ZM forms a diameter
a
25º
b
10º
c
20º
d
50º
e
65º
f
55º
2
An svg image showing a math problem
Find angle MNB in degrees given that MBN is 70º and NB forms a diameter
a
65º
b
10º
c
50º
d
55º
e
80º
f
20º
3
An svg image showing a math problem
Find angle BYM in degrees given that BMY is 60º and YM forms a diameter
a
60º
b
45º
c
15º
d
e
75º
f
30º
4
An svg image showing a math problem
Find angle ZRB in degrees given that ZBR is 30º and RB forms a diameter
a
45º
b
90º
c
75º
d
15º
e
60º
f
120º
5
An svg image showing a math problem
Find angle PXC in degrees given that PCX is 50º and XC forms a diameter
a
40º
b
130º
c
70º
d
85º
e
20º
f
35º
6
An svg image showing a math problem
Find angle BCD in degrees given that BDC is 20º and CD forms a diameter
a
115º
b
25º
c
40º
d
100º
e
70º
f
55º
7
An svg image showing a math problem
Find angle ZBN in degrees given that ZNB is 60º and BN forms a diameter
a
15º
b
105º
c
90º
d
30º
e
f
60º