1 / 12

Angles

Angles. Notes. Name the three angles in the diagram. WXY, or YXW. YXZ, or ZXY. WXZ, or ZXW. You should not name any of these angles X because all three angles have X as their vertex. EXAMPLE 1. Name angles.

velika
Download Presentation

Angles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Angles Notes

  2. Name the three angles in the diagram. WXY, or YXW YXZ, or ZXY WXZ, or ZXW You should not name any of these angles X because all three angles have Xas their vertex. EXAMPLE 1 Name angles

  3. Use the diagram to find the measure of the indicated angle. Then classify the angle. a.KHJ b. GHK c. GHJ d. GHL EXAMPLE 2 Measure and classify angles SOLUTION A protractor has an inner and an outer scale. When you measure an angle, check to see which scale to use.

  4. o a.HJ is lined up with the 0 on the inner scale of the protractor. HKpasses through 55 on the inner scale. So, mKHJ = 55 . It is an acute angle. o o o b.HG is lined up with the 0 on the outer scale and HKpasses through 125 on the outer scale. So,mGHK = 125 . It is an obtuse angle. o o o c.m GHJ = 180. It is a straight angle. o d.m GHL= 90. It is a right angle. EXAMPLE 2 Measure and classify angles

  5. ANSWER PQR , PQS, RQS . PQS is a right angle . for Examples 1and 2 GUIDED PRACTICE 1. Name all the angles in the diagram at the right.Which angle is a right angle?

  6. Straight Angle ANSWER for Examples 1and 2 GUIDED PRACTICE 2. Draw a pair of opposite rays. What type of angle do the rays form?

  7. o ALGEBRAGiven that m LKN =145 , find m LKM andm MKN. STEP 1 Write and solve an equation to find the value of x. mLKN = m LKM + mMKN o o o 145 = (2x + 10)+ (4x – 3) EXAMPLE 3 Find angle measures SOLUTION Angle Addition Postulate Substitute angle measures. 145 = 6x + 7 Combine like terms. 138 = 6x Subtract 7 from each side. 23 = x Divide each side by 6.

  8. STEP 2 Evaluate the given expressions when x = 23. mLKM = (2x+ 10)° = (2 23+ 10)° = 56° mMKN = (4x– 3)° = (4 23– 3)° = 89° So, m LKM = 56°and m MKN = 89°. ANSWER EXAMPLE 3 Find angle measures

  9. 3. Given that KLMis straight angle, find mKLN andm NLM. STEP 1 Write and solve an equation to find the value of x. m KLM + m NLM = 180° (10x – 5)° + (4x +3)° = 180° = 180 14x – 2 = 182 14x x = 13 for Example 3 GUIDED PRACTICE Find the indicated angle measures. SOLUTION Straight angle Substitute angle measures. Combine like terms. Subtract 2 from each side. Divide each side by 14.

  10. STEP 2 Evaluate the given expressions when x = 13. mKLM = (10x– 5)° = (10 13– 5)° = 125° mNLM = (4x+ 3)° = (4 13+ 3)° = 55° mKLM = 125° mNLM = 55° ANSWER for Example 3 GUIDED PRACTICE

  11. STEP 1 Write and solve an equation to find the value of x. m EFG + m HFG m EFG EFG is a right angle = = 90° (2x + 2)° + (x +1)° = 90° = 90 3x + 3 = 87 3x x = 29 for Example 3 GUIDED PRACTICE 4. Given that EFGis a right angle, find mEFH andm HFG. SOLUTION Substitute angle measures. Combine like terms. Subtract 3 from each side. Divide each side by 3.

  12. STEP 2 Evaluate the given expressions when x = 29. mEFH = (2x+ 2)° = (2 29 +2)° = 60° mHFG = (x+ 1)° = (29+ 1)° = 30° mEFG = 60° mHFG = 30° ANSWER for Example 3 GUIDED PRACTICE

More Related