# IGCSE Mathematics Paper-1: Specimen Questions with Answers 134 - 135 of 175

## Question number: 134

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A square ABCD has two diagonals, O is center. Angle ODA = . Calculate angle OAD. A Square is Making Four Triangles in It Find the angle OAD by using given angle and logic

### Explanation

Here,

As we can see in the figure AC and BD are intersecting lines in square.

Angle ADO = , as we know angle made by intersecting of diagonal is so angle AOD =

Now, in any triangle addition of all angles will give

So, in

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## Question number: 135

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In the diagram, and a line LM passing through point D. Angle . Find the angle LDB, CDM and ADL. AB⊥CD and a Line LM Making an Angle Find the angle LDB by using given angle and lines

### Explanation

Here, and a line LM passing through point D.

Now, Angle is given.

• So, angles BDM and ADL are vertical angles as shown in figure, which will be always same.

So, angle

• Now, angles BDM and CDM are complimentary angles, as shown in figure.
• Two angles whose adding gives are called as complimentary angles.

So,

Now, , so .

So,

Thus, angle