Self Practice 2025-01-17 Geometry: Written Sol

[PSMO S1.10.2]

An angle is 20° greater than its complementary angle. What is the degree of the supplementary angle of its complementary angle?

[PSMO S1.10.3]

For an angle, the sum of its supplementary angle and complementary angle is 60° greater than the difference between its supplementary angle and complementary angle. Find the degree of the complementary angle of this angle.

[PSMO S1.10.4]

As shown in the diagram, ∠AOB = 90°, ∠AOC is an acute angle, ON bisects ∠AOC, and OM bisects ∠BOC. Find the degree of ∠MON.

[PSMO S1.10.5]

As shown in the diagram, ∠AOB and ∠COD are the complementary angles of ∠BOC, and OE and OF are the bisectors of ∠AOB and ∠COD, respectively. If ∠BOC = 50°, find the degrees of ∠EOF.

[PSMO S1.10.6]

Given an angle, the sum of its supplementary angle and three times its complementary angle is equal to 11/12 of the round angle. Find the degree of this angle.

[PSMO S1.10.7]

As shown in the diagram, the lines AB and CD intersect at O, OE bisects ∠AOC, and ∠BOC -∠BOD = 20°. Find the degree of ∠BOE.

[PSMO S1.10.8]

As shown in Figure 10.13, how many angles are there in total?

[PSMO S1.10.11]

As shown in the diagram, it is a 3 × 3 grid. Find the degree of ∠1 + ∠2 + ∠3 + ∠4 + ∠5 + ∠6 + ∠7 + ∠8 + ∠9.

[PSMO S1.10.13]

At 8:20, what is the degree of the angle formed by the hour hand and the minute hand?